Transformation of previously derelict areas

Historically, the area of San Paolo in Cagliari has suffered from environmental degradation and illegal dumping, making it an unsightly entrance to the city. In 2022, the Città Metropolitana di Cagliari, initiated a project to transform this degraded area into a urban park featuring 7,000 new plants, including olive trees, junipers, lentisks, myrtle, rosemary, tamarisks, and Aleppo pines. Managed by the municiplaity of Cagliari, and funded by a €500,000 grant from the Ministry of Ecological Transition, this initiative will cover 4.7 hectares between Via San Paolo and the Santa Gilla Lagoon, creating a natural corridor connecting the city to the lagoon. The project aims not only to restore the land but also to enhance both metropolitan and municipal environmental requalification plans.
A multidisciplinary team, including a forestry technician, agronomist, and biologist, developed the project to ensure it is environmentally sustainable and suited to the local ecosystem.
The work on the project began in June of 2022 with land preparation, removal of invasive species, and waste collection, resulting in the clearing of over 5 tons of rubbish. By December, around 3,000 plants had already been planted, with the remaining work, including the installation of an irrigation system, scheduled for completion by January 2023. The selected plant species are fast-growing, and within two years, the shrubs are expected to reach a height of about two meters. The park is planned to open to the public in 2024, providing a new green space for walking and outdoor activities.
The San Paolo urban park project has encountered obstacles, mainly due to the expropriation of buildings, leading to legal disputes, permit delays, and a temporary halt caused by a tender-related issue. The site is currently overgrown and unused, showing clear signs of neglect. (Refs. 1, 2, 3, 4 & 5).

The Africatown Connections Blueway project aims to create a recreational water trail by linking 14 culturally and historically significant points along a 10-mile route (Ref 1). Central to this initiative is the preservation of Africatown's rich heritage and natural resources. The project seeks to reconnect residents of Africatown, descendants of the original founders of this self-governing community, which maintained a strong sense of African cultural heritage, to waterways that were historically vital for food, transport, and spiritual practices (Ref 1). By restoring access to these waters, the community can address both environmental and social issues, promoting eco-tourism and business growth while safeguarding cultural heritage (Ref 2). Local leaders emphasize the environment’s role in healing the community and preserving history, highlighting how this initiative can provide economic opportunities and improve quality of life (Ref 2). The project seeks to address the environmental injustices that Africatown communities have endured for decades. The area surrounding Africatown has long been dominated by harmful industries, including aluminium plants and paper mills, which have heavily polluted the water and restricted residents' access to it (Ref 1). With support from the National Park Service and contributions from Mississippi State University, the Blueway transforms neglected river access points into recreational areas, promoting environmental stewardship and cultural awareness (Ref 2).

Brookley by the Bay is a 98-acre new waterfront park project along Mobile Bay's western shore (Ref 1). The park aims to reconnect people with the Mobile waterfront and coastal ecosystem (Ref 2). The area, once an abundant mosaic of tidal marshes, forested wetlands, and shallow lagoons, became a port, leading residents to lose contact with the natural landscape (Ref 2).
The park serves both recreational and environmental purposes, aiming to create and restore areas that enhance habitat resilience and allow coastal ecosystems to thrive (Ref 1). It features sports facilities, including kayaking, volleyball, golf, and biking, along with social gathering and educational spaces such as an amphitheatre lawn, a performance pavilion, and picnic tables (Ref 3, Images 1-3). The park provides safe and equitable access for all Mobile residents to nature, beaches, tree canopies, open fields, and varied shorelines, all connected by pedestrian and bike lanes (Ref 2). The project also focuses on habitat enhancement and restoration for biodiversity (Ref 3, Images 1 & 4), as well as flood protection through shoreline get-downs, vegetated edges (Image 4), and undulating berms and swales that serve as a layered protection system against stormwater and coastal flooding (Ref 2).
The development of Brookley by the Bay was guided by input from over 300 community members (Ref 1), local stakeholder organizations, and project partners, with the goal of establishing a more resilient, accessible, and enduring space for generations to come (Ref 2).

The PARK(ing) project, completed in April 2022, is an urban private intervention in Core City neighborhood in Detroit, that re-imagines a vacant 24,000-square-foot lot into a dual-purpose public park and a 28-car parking lot. Designed by Julie Bargmann of D.I.R.T. Studio, in collaboration with Prince Concepts and in-house landscape designer Andrew Schwartz, this innovative green space harmonizes urban infrastructure with natural elements. The site is punctuated with 78 newly planted trees, including sumac, maple, and evergreen species, creating an environment rich in vegetation that seamlessly integrates with its urban surroundings.
The design incorporates permeable pavers and sloped berms, which effectively manage storm-water by absorbing and channeling rainwater, mitigating the risk of flooding—an often-overlooked challenge in traditional parking lots. This approach reflects sensitivity to the local environment and a commitment to sustainable urban design.
By day, the park discreetly functions as a parking facility, with cars nestled among dense greenery, while by evening, it transforms into a public garden, extending the communal space of Core City Park. This dual functionality addresses the needs of a car-dependent community while promoting walkability and enhancing the neighborhood's ecological footprint.
PARK(ing) exemplifies a shift in Detroit's urban planning, moving away from the car-centric developments of the past toward a more balanced relationship between people, nature, and infrastructure. The project stands as a testament to the evolving identity of American cities, particularly those like Detroit, historically shaped by the automobile. It offers a vision of urban spaces that prioritize community well-being and environmental stewardship while acknowledging the realities of modern urban life. (Ref. 1, 2)

The "Line Park" project in Belgrade aims to create a continuous green belt spanning 4.6 kilometres and covering over 48 hectares. As such, the project will revitalize the former railway corridor from "Beton Hala", just below the Belgrade Fortress, to the Pancevac Bridge. Inspired by notable urban parks like New York's "High Line", Moscow's "Zagrađe," and Toronto's "Rail Corridor," it will become a major recreational destination and also help to alleviate the pressures from the city's heavy air pollution and summer heat (Ref. 5, 6).
The park will be divided into ten thematic sections dedicated to aromatic plant and flower gardens, urban gardening and beekeeping, sports facilities, a newly built university campus and more. Additionally, there will be an amphitheatre and facilities for outdoor education. To further integrate green infrastructure, new buildings will have green roofs and walls (Ref. 2,5). Ultimately, the park integrates a number of amenities into the entire city.
The development of the park also introduced innovative co-creation mechanisms in terms of governance and planning. Since Belgrade is part of the multinational CLEVER Cities Initiative, the city's Secretariat for Environmental Protection suggested the use of the site as a pilot test for introducing nature-based solutions in urban planning and with diverse stakeholders' input. Several workshops, focus groups, and consultations took place between 2019 and 2021, which facilitated the diversity of ideas that have been adopted into the official construction plan (Ref. 1, 2). Despite these successes, civil society groups raise concerns over the extraordinary cost of 70 million euros, displacement of Roma communities and the interest of real estate developers that may undermine the project's original cause (Ref. 3, 8).

According to the FAO, in 2022, 16.6 million Peruvians faced moderate or severe food insecurity, representing an increase of 1.5 million compared to the previous year (3). This situation was exacerbated by the health crisis, inflation, and job losses, leaving three out of ten Peruvians in poverty in 2021. The situation was particularly critical in Metropolitan Lima and Callao, with 14% of families reporting difficulties in acquiring protein-rich foods due to their precarious economic situation (2).
In response to this food crisis, the Municipality of Lima implemented the "Lima te Cuida" (Lima Takes Care of You) initiative, in which residents from vulnerable areas got training to create urban gardens and produce organic compost to help the community kitchens in these areas become self-sustainable (1, 2). An example of this initiative is the community garden in A.H. Villa Mosha in San Juan de Lurigancho, where a community garden has been built, and community members have been trained in small-scale planting, cultivation, care, and harvesting of various foods (2).
This initiative has been supported by the MUSA project "Mujeres Unidas por la Seguridad Alimentaria y Ambiental" (Women United for Food and Environmental Security) as part of the project "Alimentando a Lima desde Adentro" (ALDA) (Feeding Lima from within), which has had an impact in eight districts of Lima to strengthen food security (3). In addition to promoting urban agriculture, the project seeks to influence public policy through training and development of proposals to promote urban agriculture at the local level (4).

The Joe Louis Greenway is a 27.5-mile recreational pathway designed to create safe, connected, and equitable spaces throughout Detroit. It will link 23 neighborhoods across Detroit, Hamtramck, Highland Park, and Dearborn, connecting them to each other and to the Detroit riverfront. The greenway will transform a blighted, abandoned rail corridor into a park that runs through the heart of Detroit's communities. (Ref. 2, 3)
This project is guided by a Framework Plan funded by the Ralph C. Wilson, Jr. Foundation and shaped by extensive community input. Residents voiced a strong desire for the greenway to provide off-street recreation and increased access to green spaces across Detroit. Additionally, they advocated for the restoration and remediation of former industrial sites, which the Conrail section of the greenway will address. (Ref. 4) The design incorporates stormwater management to mitigate flooding, native meadow plantings to support bird habitats, and tree-lined paths for shade and improved air quality. The Framework Plan ensures the Joe Louis Greenway will transform infrastructure that once divided neighborhoods into one that unites them, reconnects natural systems, drives economic redevelopment, and fosters a resilient social network. (Ref. 13)
The concept originated in 2007 with the Friends of the Inner Circle Greenway local NGO and became part of the Detroit Greenways Coalition Network Vision in 2009. The Detroit Greenways Coalition Network Vision is a comprehensive plan developed by the Detroit Greenways Coalition (NGO), an organization dedicated to promoting non-motorized transportation and green infrastructure throughout the city. After years of advocacy and collaboration with the city of Detroit, the project’s route was finalized. In 2017, Mayor Mike Duggan announced the greenway would be renamed in honor of Joe Louis, the legendary boxer and Detroit native who championed African Americans' rights and symbolized social justice. (Ref. 1, 2,)

The Floating University was initiated in 2018 at the rainwater retention basin of the former Tempelhof airport in Berlin. Though not an official university, it serves as a space for transdisciplinary, communal learning, transforming an abandoned urban site into a vibrant community resource. The project reclaims the basin, hosting workshops and events that range from ecological lectures to cultural and art programs, fostering collaboration between diverse disciplines and communities.
The architecture collective raumlaborberlin originally envisioned the project as a six-month initiative. Artists, universities, and seminar groups contributed to designing the space and organizing workshops. However, due to its success, an NGO, Floating e.V., was established to sustain the project. Today, the NGO manages the site and continues its mission of engaging communities with urban and ecological themes.
After Tempelhof airport closed in 2008, the basin was infrequently cleaned, leading to contamination and sediment accumulation. Over time, a wetland ecosystem emerged, attracting plants, insects, birds, mammals, and amphibians. This natural development complements the Floating University’s infrastructure, which consists of open timber structures like a kitchen, art installations, communal spaces, vertical gardens, gardening beds, and an auditorium. These structures integrate seamlessly with the basin’s existing technical framework and wetland environment.
Floating e.V. aims to make the basin accessible to Berlin’s urban population while sparking discussions about urban climate, resource management, and water cycles through diverse and artistic programs. Smaller initiatives focus on specific ecological themes, such as plant diversity and soil health, through projects like a seed archive and soil lab.
The Floating University exemplifies how abandoned urban spaces can be revitalized into hubs for learning, creativity, and ecological awareness. (1-3, 8, 9)

A community garden opened in 2023 on the Technological University (TU) Dublin Blanchardstown campus. This environmental education and social inclusion project is a collaborative effort involving Fingal County Council, Global Action Plan Ireland, TU Dublin, and the local community. It provides a space for local groups and schools to grow fresh produce, reconnect with nature, and foster a stronger sense of community.
Rooted in a successful template developed by Global Action Plan in Ballymun, this initiative promotes social and cultural inclusion alongside environmental education. The Green Living & Sustainability Community Garden (GLAS) aims to create an inclusive environment that welcomes individuals of all ages, abilities, and backgrounds. More than a site for cultivating plants, flowers, and vegetables, the garden serves as a hub for fostering social connections, enhancing well-being, and offering valuable educational opportunities.
The garden provides individuals with the chance to engage in social horticulture, exploring the connections between food, health, biodiversity, and global issues such as climate change. It operates on organic and regenerative principles, with all tasks and harvests shared by volunteers. Additionally, the garden will support youth gardening projects and public workshops on topics such as growing food, composting, water harvesting, and waste management. Beyond its environmental benefits, the garden helps people connect with one another, positively impacting social, physical, and mental well-being.

The city-wide project Urban Trees for Berlin was launched in 2012 with an ambitious goal: to plant 10,000 roadside trees within five years. This campaign, a key part of the Berlin Senate's Urban Green Space Strategy, is a collaboration between the Senate Department responsible for the environment and Berlin’s district authorities. Initially set to end in 2017, the campaign was extended through 2026.
The project was created to address the loss of numerous roadside trees that were removed due to age, pests, climate stress, and other factors. Limited funds had been available to replace these trees, resulting in negative impacts on Berlin's urban climate, including higher temperatures and worsened air quality, which affect both residents and visitors. The campaign aims to reverse these impacts by securing funding for new trees, restoring greenery to the city streets, and promoting a lasting positive image of Berlin’s urban trees.
The campaign operates on a co-funding model, where individuals, organizations, and companies donate €500 per tree (individually or collectively), with the Senate covering the remaining costs from the state budget (approximately €2,000 per tree). The planting schedule and locations are organized twice annually, with information shared online to keep the public informed.
In 2022, a new assessment of the project’s progress was conducted, commissioned by the Senate to the Arbo-tec office. Around 1,000 of the 3,500 trees planted as part of the campaign by autumn 2022 were evaluated. The selected locations included plantings from all previous construction phases, spanning 12 Berlin districts, with each district having 80 trees assessed from various phases and construction lots. This comprehensive evaluation is intended to ensure the long-term success and sustainability of the Urban Trees for Berlin initiative. (3, 4)