Vacant or abandoned land

The Detroit RiverWalk is an urban development project along the Detroit River, designed to reconnect residents with their waterfront and revitalize a historically industrial area. Once characterized by abandoned buildings and industrial debris, the riverfront between the MacArthur and Ambassador Bridges had long been inaccessible to the public. To address this, the Detroit Riverfront Conservancy was established in 2003 to lead the redevelopment of this space.
The RiverWalk currently stretches along a 3.5-mile section, with plans to expand to 5.5 miles, integrating ecological restoration, public access, and recreational opportunities. The esplanade features native landscaping, artistic elements, and amenities, including four pavilions, a custom carousel, and areas for fishing, walking, biking, and inline skating.
Environmental remediation has been a crucial part of the project. In collaboration with the U.S. Environmental Protection Agency’s Great Lakes National Program Office, the Detroit Riverfront Conservancy successfully cleaned up 13,000 cubic yards of contaminated sediment, significantly reducing pollution and contributing to the removal of the Detroit River from the list of the most polluted sites in the Great Lakes. Furthermore, the project also includes greenways, park creation and revitalization.
The RiverWalk is not just a public space; it symbolizes Detroit’s transformation from a Rust Belt city to a sustainable urban environment. It exemplifies the power of public-private partnerships in revitalizing urban areas. The RiverWalk continues to expand, with plans to connect various parks and extend to the Ambassador Bridge, further enhancing the city’s waterfront. Its success was recognized in 2021 when it was named the Best Riverwalk in America by USA Today, cementing its status as a model for urban renewal and community engagement. (Ref. 1, 2, 3, 4)

Civic Space Park, located in the heart of Phoenix, Arizona, is a notable example of urban design aimed at addressing the region’s increasing urban heat. In Phoenix, rising temperatures affect health, safety, comfort, and economic growth, and this impact is expected to worsen over time. In response, the park was developed to transform an underused site into a vibrant public space that prioritizes community engagement, sustainability, and urban revitalization.
The project was realized through a public-private partnership between the City of Phoenix and Arizona State University, with strong community involvement shaping its development. This collaboration led to the “Urban Weave” concept, a design that embodies the identity and values of the local community.
Civic Space Park was designed with several goals in mind. Increasing the tree canopy was essential to help reduce the urban heat island effect and improve air quality. Creating a welcoming area for social interaction, recreation, and relaxation was equally important to enhance community well-being. Water conservation was also prioritized, achieved through innovative stormwater management techniques such as permeable paving and underground infiltration. The park incorporates renewable energy generation as well, with on-site solar power helping to reduce energy consumption.
One of the park’s unique features is its extensive use of pervious concrete paving, designed to allow stormwater to permeate directly into the subsurface. However, during installation, it became clear that placing the material over highly compacted soil limited water infiltration. To improve its effectiveness, future designs could include a plastic vapor barrier beneath the permeable paving to capture water and direct it to planting beds. This adjustment would enable the paving to act as a collection and storage system, gradually releasing water into the surrounding vegetation.
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Baštalište is an organic community garden initiative located in the town of Slanci, some 20 minutes from the city centre of Belgrade (Ref. 3). It is one of the first initiatives of its kind in Serbia, emerging after organizations such as WWOOF Serbia and the Belgrade Flower Festival, along with activists and citizens, united with the goal of growing vegetables for their own needs. Additionally, they aimed to highlight the numerous neglected and abandoned urban spaces in the city that could be repurposed in this manner (Ref.1). Even though more and more people would like to join Baštalište, the community has been struggling to grow beyond their original plot of 1800 m2, shared between some 30 people of mixed demographics (Ref. 3). They have turned to the municipality to provide more such spaces for urban community gardening but their appeals bear little success (Ref. 2,3). Despite their spatial constraints, the initiative remains open to anyone who would like to visit and help while being financed by membership fees (Ref. 1,2,3). The initiative hopes to eventually scale this type of activity, drawing inspiration from the example of Zagreb, where over 2,000 garden communities were established within 2.5 years after the city decided to repurpose its neglected areas (Ref. 2).

Lafayette Greens is a transformative urban green space and community garden located in downtown Detroit, occupying a parcel of 1720 sqm that once housed the historic Lafayette Building. Following the building's demolition in 2010, the site, situated near Compuware headquarters and the Detroit Federal Building, was re-imagined through a public-private partnership into a productive urban garden (Ref.1, 6). The garden was designed in 2012 for a local software company, Compuware, which after completion gifted it to a local NGO, The Greening of Detroit, in 2014. Lafayette Greens serves as a green oasis in a bustling urban environment, offering city workers, residents, and visitors a space to relax and engage with nature. The garden produces chemical-free fruits, vegetables, herbs, and flowers, and since 2019, has focused on cultivating a certified pollinator habitat, essential for supporting urban biodiversity. The garden also provides educational programming, including classes on pollinators like bees and birds, and the DIG - Detroiters in the Garden series, in collaboration with Fort Street Presbyterian Church’s Open Door program, fostering community involvement and environmental stewardship. (Ref.2)

Del Nervi Park is a project co-led by the Port System Authority of the Sardinian Sea and the Municipality of Cagliari. Completed in 2021, it transformed a long-abandoned and degraded area on the Cagliari waterfront into a vibrant green space. The two-hectare site surrounds a 1950s industrial building and underwent extensive redevelopment to enhance its structural integrity and convert it into a public park. With a budget exceeding 5 million euros, the project prioritized green investments by creating new pedestrian and cycling paths, along with green spaces featuring local plants, flower beds, grass, and lawns.

Nervi Park is set to become a key destination for leisure, sports, and cultural activities, while also providing the Cagliari community with greater access to green spaces. The environmental and urban renewal efforts aimed to beautify and modernize the area, with future development plans focusing on long-term management and the introduction of commercial activities to further enhance the space
The project faced significant barriers, including prolonged disruptions due to the COVID-19 pandemic, which halted work for about eight months. (Refs. 1, 2, 3 & 4).

Giulia's Farm is the first project launched by the Italian NGO Terre Colte in Sardinia, focused on transforming unused agricultural plots into a productive community garden. Initiated in 2014, the project covers approximately 3,000 square meters (out of 18,000 sqm owned by the NGO). The garden leases 50-square-meter plots to local residents, known as "ortisti," who cultivate the land using organic and natural farming methods. This approach not only revitalizes neglected land but also strengthens community bonds and promotes sustainable agriculture (Refs. 1 & 2).
The project operates on a cooperative model, ensuring that the land remains accessible and productive while fostering a connection between people and the environment. Participants share resources and knowledge, creating a network of mutual support that enhances both social and environmental resilience.
Beyond its agricultural impact, Giulia's Farm aims to preserve Sardinia's agricultural heritage and combat land speculation. By involving the community in farming, the initiative helps protect these plots from being sold for non-agricultural purposes, ensuring they remain dedicated to food production. The project also demonstrates the potential for reclaiming abandoned land, fostering local food production, and building a more sustainable and resilient food system.
Giulia's Farm has gained attention as a replicable model for other regions facing similar challenges of land abandonment and environmental degradation (Refs. 2, 3 & 4).

The Three Mile Creek Greenway Trail project aims to transform the existing creek into a valuable community asset by developing a multi-use greenway trail (Ref 1). This greenway will connect various parts of the city through walking and biking paths, linking neighbourhoods, parks, and commercial districts while providing access to unique natural areas (Ref 2). The creek having been adandonned for decades (Ref 5), the initiative seeks to turn 3 Mile Creek (3MC) into a vibrant natural corridor that fosters recreation, education, and economic activities (Ref 1, Ref 2). The project aims also at reducing pollutants in the waterway, restoring natural stream channels, and maintaining flood protection (Ref 1).
The 3MC Greenway Trail is expected to become a key feature of Mobile's urban landscape, offering numerous benefits. These include enhancing community health, both mental and physical (Ref 2), and stimulating the local economy by increasing property values, tax revenues, and opportunities for recreation-related businesses and job development (Ref 2). Additionally, the trail will improve community connectivity by linking neighbourhoods, parks, and schools, thereby fostering a stronger sense of community and better access to public spaces (Ref 2). Lastly, the project will contribute to environmental restoration through stormwater management, pollution reduction, and natural habitat preservation (Ref 2).
The greenway is part of a plan to restore the health of the Three Mile Creek watershed and is the first major piece of a long-term Mobile Greenway Initiative (MGI) (Ref 4).

The Circle Forest project, led by Arboretum Detroit in partnership with Detroit Future City, is transforming a vacant lot the size of a football field in the Poletown East neighborhood into a green space. Once used as a dumping site, the area is being revitalized with 200 native trees, including oak, elderberry, white pine, and juniper. Supported by local groups like Detroit Audubon, Singing Tree, and the US Fish and Wildlife Service, the project aims to improve environmental quality and provide better access to nature for residents. Since 2019, over 120 trees have been planted, with plans to develop a native meadow. This initiative offers a space for recreation and reflection, benefiting the local community, including a nearby nursing home and rehabilitation center. Beyond ecological restoration, Circle Forest fosters connections to indigenous knowledge and respects the wisdom of the original stewards of the land. (Ref.1, 2)

Spaces of Opportunity is an initiative created by several organizations in Phoenix, that aims to bring food security and sustainability to the south Phoenix community. The initiative aims to reach its goals through its community garden that incorporates 19 acres of barren land (dessert) that can be used by locals for growing food and earning an income while providing the community organically grown produce. The mission is to enable all South Phoenix families to have affordable access to healthy food, active living and healthy roots of their cultures (1, 2, 4, 6, 8).
The initiative started in 2011 when several local actors formed a coalition with a shared vision of improving well-being by addressing the natural, built, and social environments. Spaces of Opportunity is the only local food system of its kind in the Phoenix metropolitan area, and unique in the country for the diverse strengths of the committed partner organizations and their shared vision to bring food security, build sustainability, and cultivate community. (8)

The Estufa Fria de Lisboa (Cold Greenhouse of Lison), located on the south-facing slope of Park Eduardo VII in Lisbon and part of the city's green corridor (Corredor Verde de Monsanto) aims to integrate leisure, culture, and education opportunities to promote plant biodiversity conservation within a sustainability framework (Ref. 1). Cold Greenhouse refers to the fact that there is no heating system on the premises, and it also refers to one of the three gardens (Ref. 5). The greenhouses were created in an old quarry dedicated to rock extraction, and these lush gardens are now comprised of three distinct greenhouse environments: cold, warm, and sweet (Ref. 1). These greenhouses collectively house over 300 plant species from diverse continents, including rare species (Ref. 2).
The garden's design integrates natural water features, with watercourses and waterfalls and statuary elements. Since the opening of its Interpretation Center in 2016, the Estufa Fria has expanded its role as an educational resource, hosting exhibitions and activities related to botany and urban green structures. Since 2016 the project has been focused on its educative agenda with the development of a set of pedagogical resources for preschoolers, students from ages 6 to 12 years old and their teachers, and with guided visits. (Ref 1, 2)