Central Business District / City Centre

The Tirana Vertical Forest is part of the city's 2030 Master Plan and aims to enhance urban biodiversity and create green spaces through innovative urban design (Ref. 1,2). The project was developed by Stefano Boeri Architetti, the same studio that has designed similar, well-known structures in cities like Milan, Utrecht and Nanjing (Ref. 6). The completion of the 21-floor building is expected in late 2024 and will feature 105 apartments and a commercial ground floor as well as 145 trees and over 3,200 shrubs and bushes which are integrated into the balconies and façade of the project (Ref. 1,2,3). Various Mediterranean plants have been incorporated, including colourful, scented and aromatic types, which harmonize with the local ecosystem. To maximise the space available for green features, a dynamic structure with alternating balconies and full-height windows has been built (Ref. 1,2). Ultimately, the project anticipates improving air quality, reducing noise, and providing insulation. The greenery is expected to capture fine particulate matter and up to 8 tones of Co2 per year while also creating a healthier microclimate for those inside the building (Ref. 1,6).

The City of Seville has carried out four tree planting campaigns between 2020 and 2024, aiming to meet the goals of its Urban Tree Management Plan for Seville [Ref. 2-7]. The intervention as described here is based on the planting campaigns to date, but as the Management Plan spans from 2019 to 2039, more campaigns can expected in the future. The tree management plan aims to provide guidelines for the planning of trees in the city to maximise their value and minimize conflicts. As part of the process, the current state of the tree population in Seville has been evaluated. The management plan describes the ecosystem services of trees related to climate adaptation, biodiversity and public health. It also identifies challenges and conflicts that may arise due to urban trees and their management [Ref. 1]. The plan has a goal to increase the tree cover in Seville by 5 % over 20 years, which leads to the ambition of planting 5000 trees yearly and the tree planting campaigns over the last years. Between 2020 and 2024, about 1000-5000 trees have been planted each year [Ref. 1-5].

The greening of the Luceafarul theater esplanade is an initiative that is part of a corporate social responsibility strategy by the real estate company IULIUS (3, p. 86 & 89). The initiative aimed to expand and complement the green spaces and landscape design of the company's urban ensemble, Palas, located in the center of Iași (1 & 2). The space was previously occupied by a building owned by the company (5). Initially, the plan was to transform the building into a business center after donating it to the municipality (8). However, IULIUS and the Municipality of Iași agreed to demolish the structure and design a public space for the citizens instead (5 to 8). This decision was also influenced by the public’s desire to keep the area open, maintaining a clear view of the historical landscape, which was later incorporated into the municipality’s urban planning (8 & 9).
The design features a green field of 2,100 square meters, including 35 trees of various species (chestnuts, plane trees, and Ginkgo Biloba imported from nurseries in Italy) and 3,000 shrubs and bushes (1 & 2). The vegetation is maintained through an automated irrigation system (1 & 2).
The initiative aims to improve access to green spaces in Iași (3, p. 86) and to provide a space for recreation, relaxation, and leisure, with benches installed throughout the area (1 & 2). IULIUS intentionally places green space projects in central urban areas to ensure they are accessible to all residents (3, p. 86). Additionally, the municipality requested that the green space enhance the area's microclimate and improve the aesthetic appeal of the surrounding cultural landmarks (9, p. 6).

Liquid 3 is the first urban photo-bioreactor in Serbia, developed by an interdisciplinary team at the Institute for Multidisciplinary Research at the University of Belgrade (Ref. 1,2,3). Prompted by an appeal of the United Nations Development Programme (UNDP), the team was eager to find novel approaches to combat the city's severe air pollution issues while being space efficient and providing year-round benefits (Ref. 3). The key to the bioreactor are algae which are very efficient in sequestering carbon and filtering heavy metals from the air (Ref. 2). A Liquid 3 feature can be quickly set and occupies a plot of only 3 m². Some of its benefits include its ability to withstand high levels of air pollution and its ease of installation on surfaces like walkways and other sealed infrastructure (Ref. 2,3). Additionally, by design, Liquid 3 integrates amenities such as power outlets, a bench, and nighttime lighting (Ref. 1). The selected strain of algae can tolerate temperatures between 5-35°C making it deployable all year. However, monthly maintenance is required, during which the water and algae are replaced—both of which can be repurposed, for example, as fertilizers (Ref. 6).The project has received global media coverage as well as a prize for the best innovative and climate-smart solution in Serbia. Its success has prompted the installation of two more such bioreactors in Serbia, with interest coming from other countries such as Hungary and the UAE (Ref. 1,4).

In 2022, the municipality of Cagliari launched a project to revitalize Viale Trieste, one of its avenues, by redesigning its roads and pedestrian areas and adding new green spaces. The project covers approximately 1,300 meters and 36,500 square meters, and will be completed in two phases, each focusing on different sections of the avenue. With a budget of 12 million euros, funded by municipal, national, and EU resources, the aim is to transform Viale Trieste into a vibrant, accessible, and attractive space for everyone.

The renewal will introduce new green spaces and improved drainage systems to enhance soil permeability. As part of this, some trees will be relocated to other areas of the city to address root issues and improve survival rates. Dead or unstable ficus trees will be removed, while 79 new trees will be planted. Older ficus trees will be relocated to city parks, with younger ones planted along the avenue to prevent pavement damage and promote sustainability. The project also includes upgrading water supply and drainage systems to manage stormwater more effectively, reducing the risk of flooding and improving sustainability. Public lighting will be modernized, with new street lamps and dedicated lighting for pedestrian and bicycle paths to make the area safer and more welcoming after dark.

However, the community has expressed concerns about the project, citing safety issues, delays, disruptions, and poor communication from officials. There is also significant opposition to replacing the historic ficus trees, valued for their environmental and historical significance, with Chinese pear trees and younger ficus (Refs. 1, 2, 3, 4, 5, 6, 11, 16).

The "Urban Farms in Gdańsk" project, launched in 2018, is an innovative educational initiative spearheaded by the Gdański Zarząd Dróg i Zieleni, Fundacja Gdańska, and dedicated volunteers. This project aims to inspire Gdańsk residents to cultivate herbs in their home gardens and balconies while emphasizing the importance of preserving urban greenery. The initiative not only promotes sustainable living but also fosters a deeper connection between the community and its natural surroundings.
As part of the project, two locations in Gdańsk—Grobla IV and Za Murami streets—feature 27 carefully designed planter boxes. Each box contains a thoughtfully curated selection of herbs, including culinary basil, lovage, olive herb, and dill, among others. These fragrant plants not only serve a practical purpose but also delight the senses and enhance the urban landscape. In total, 27 pots measuring 60x80 cm and 50 cm high were set up, with each labeled to describe its specific composition and plant varieties.
Approximately 500 plants were cultivated as part of this effort, showcasing a harmonious blend of practicality, education, and aesthetics. The herb gardens thrive from spring through late autumn, offering an ongoing visual and sensory experience. They serve as a testament to the potential of urban spaces to support greenery, community engagement, and ecological awareness.
This initiative also underscores the importance of individual contributions to urban green spaces. By growing herbs, residents not only enhance their own surroundings but also play an active role in maintaining the city's ecological balance. The "Urban Farms in Gdańsk" project demonstrates how urban agriculture can merge utility and beauty, creating vibrant spaces that benefit both people and the environment. (1-3)

In Peru, there is a significant gap in the coverage of public spaces for social interaction, environmental awareness, and cultural expression in urban areas, reaching 23.10% (3). To address this issue and commemorate the 200th anniversary of Peru's independence, the national project "Proyecto Especial Bicentenario" (Special Bicentenary Project) was launched. As part of this project, 26 Cultural and Ecological Parks are being developed throughout the country (2, 5). This initiative aims to strengthen the role of municipalities in sustainable urban planning, prioritising the well-being of citizens and promoting citizen participation (1, 3).
These parks combine ecological elements with cultural infrastructure, fostering a connection between people and nature and their Peruvian identity (5). By offering recreational and educational spaces, the goal is to raise public awareness of the importance of local biodiversity and strengthen community ties (1, 5). To ensure that these spaces meet the needs of each community, a citizen participation campaign called "Ideas for My Bicentennial Cultural Park" was implemented, allowing citizens to propose ideas from various perspectives, such as design, culture, citizenship, and the environment (5).
The San Isidro Bicentennial Park, inaugurated in 2020, is an example of this initiative. With its 20,000 square meters of green areas, cultural activities, family recreation zones, and a neighbourhood gathering centre, this park has become a new green lung for the city and a meeting place for people of all ages, with a focus on inclusion for children and the elderly (2, 4, 5). Additionally, it features a municipal community garden of 250 m2 that promotes urban agriculture and offers workshops to teach citizens about sustainable farming practices (6).

Thessaloniki has a dense urban structure with limited open and green spaces. As a coastal city severely impacted by climate change, it faces multiple interconnected challenges, including extreme weather events, flooding, and peri-urban forest fires. These issues are further compounded by the city's aging infrastructure and deteriorating buildings, increasing its vulnerability (Ref 1).
Kipos 3, a community garden, is part of the "Green Neighborhoods" project proposed in the Thessaloniki 2030 municipal resilience strategy (ibid.). Established in 2015 on a 600-square-meter plot donated by the municipality, the garden is now managed by 30 local families under the continued stewardship of the Municipality (Ref 2, 3). The garden's creation was supported by a team of architects, landscape architects, and agriculturists, and features a variety of herbs and edible plants grown using permaculture methods (Ref 3).
The garden hosts a greenhouse along a range of environmental, recreational, and educational activities, providing an opportunity to foster a more cohesive, inclusive, and resilient community. It also serves as a space for synergies and discussions about the future of the city (Ref 3, 4). Recognized as a good practice, the intervention has been showcased in national, European, and international networks (Ref 2, 4).

The "Há Vida no Meu Bairro" project is an innovative urban initiative led by the Lisbon City Council aimed at transforming the city into a "15-minute city." This concept ensures that all essential urban functions, such as commerce, green spaces, education, sports, culture, health, and social support, are within a 15-minute walk from residents' homes. The project promotes neighbourhood identity, quality of life, active mobility, and the development of safer, more comfortable public spaces. By integrating these elements, the initiative seeks to create multifunctional neighbourhoods where daily needs can be met locally, reducing dependence on cars and enhancing pedestrian accessibility (Ref 1).
Lisbon's approach is both city-wide and neighbourhood-specific, with pilot projects being developed in collaboration with the city's 24 parishes. These projects focus on improving public spaces and pedestrian mobility, reinforcing the city's commitment to sustainability and community engagement (Ref 2). The initiative also emphasizes the importance of public participation, encouraging residents to contribute to the design and development of their neighbourhoods and enhancement of local identity and green spaces (Ref 3).

Cagliari's waterfront is currently characterized by extensive soil sealing, which has rendered the soil impermeable, leading to a loss of biodiversity and contributing to the urban heat island effect. Additionally, the waterfront is disconnected from the city due to heavy traffic. In 2023, the Municipality of Cagliari launched the "Green Promenade for Cagliari’s Seafront" project, aimed at revitalizing the waterfront and reconnecting the city with its coastal heritage. Led by Stefano Boeri Architetti, the project seeks to transform the area into a continuous green space that integrates pedestrian pathways with shaded public areas, functioning as a "green lung" to mitigate urban heat and enhance biodiversity.
The initiative will introduce over 200 new trees and 5,700 square meters of green space, creating a park that beautifies the area, improves air quality, and lowers local temperatures. A key focus of the project is fostering cultural and social inclusion by developing new community hubs that encourage diverse activities and strengthen social cohesion. Additional features include recreational areas, sports fields, and outdoor seating. (Ref. 1, 2,3)
The project also aims to enhance social inclusion, environmental sustainability, and urban connectivity, ultimately transforming the waterfront into a vibrant public space that reflects Cagliari’s identity.
However, the lengthy construction process has disrupted local businesses and reduced foot traffic, making the area less attractive during the redevelopment phase. (Refs. 10, 11, 12 & 13).