Krater, Ljubljana – Creative Laboratory in a Construction Pit by Prostorož

At the intersection of Dunajska and Topniška Street lies one of Ljubljana’s oldest abandoned construction sites—a scar left by decades of halted urban planning. Originally cleared in 1994 for a government building that was never realized, the site was left with two vast gravel pits and a legacy of dereliction. In this liminal terrain, between ruin and regeneration, Krater was born.

Krater is a temporary yet transformative architectural and landscape intervention—an experiment in cohabitation, material circularity, and ecological imagination. Developed on 4000 m² of the unused lot through a community agreement with the landowner, the project reclaims this long-inaccessible site for public use. It is a living infrastructure of transdisciplinary collaboration among architects, biologists, designers, and artists, who together reframe this “wasteland” as a testing ground for more connected, climate-conscious urban futures.

The space has been partially rehabilitated with mobile architectural elements—modular, movable, and made entirely from previously used, repurposed materials. Prior to any physical intervention, a detailed analysis of the existing ecosystem was carried out, identifying spontaneous vegetation, soil conditions, and microhabitats that had developed during decades of abandonment. This ecological mapping informed the placement and orientation of all spatial elements, ensuring minimal disturbance to the site’s natural regeneration processes. Every component introduced to the space—from the floors of discarded wood, to composting toilets upcycled from old telephone booths, to the workshop structures—had a previous life. Even the glass surfaces used throughout the site are reclaimed, bearing traces of their former functions. Almost no new materials were introduced. This commitment to radical reuse challenges conventional hierarchies of permanence and form, embracing an architectural language of impermanence, responsiveness, and care. The result is a living, evolving space—architecture in flux—shaped not just by human intention, but by the ecological intelligence of the site itself.

Krater hosts three core production labs: a papermaking station, a wood workshop, and a myco-design lab. These open-access hubs are embedded within the local ecosystem, engaging with the site’s colonizing species—pioneering, feral plants that have stabilized the damaged soil and created new microhabitats. Taking inspiration from these resilient ecologies, Krater fosters new forms of human-nature kinship through material experimentation, public education, and cultural production.

What distinguishes Krater is its approach to landscape—not as a backdrop or passive container, but as a co-creator in a continuous process of place-making. The design resists the idea of a finished product, favoring instead a curatorial, responsive mode of stewardship. The landscape is not “restored” to a prior state, but reimagined in a process of mutual adaptation—where waste becomes resource, weeds become allies, and temporary use becomes an act of future-making.

Krater shows that so-called degraded urban ecosystems hold tremendous potential—for biodiversity, microclimate resilience, and social cohesion. Its landscape design is not only aesthetic but pedagogical. It is a place where citizens can learn skills of self-sufficiency, circular thinking, ecological stewardship, and collaborative governance. Through workshops, installations, and open gatherings, Krater becomes a porous commons—an interface between knowledge and soil, between civic engagement and ecological restoration.
As cities face the twin crises of climate change and social fragmentation, Krater offers a replicable model: an adaptable, low-impact, community-driven landscape that challenges normative development paths. It invites us to see urban voids not as failures, but as fertile grounds for reinvention.

• All landscape architecture offices involved in the design of landscape:
Urban design studio Prostorož, Trajna association, Slovenian Permaculture Association, Shelter for Discarded Plants, Agrodivizija association

• All architecture offices involved in the design:
Urban design studio Prostorož, Trajna association, Slovenian Permaculture Association, Shelter for Discarded Plants, Agrodivizija association

• Other credits:
Andrej Koruza (intermedia artist and designer), Gaja Mežnarič Osole (designer, ecologist and activist), Primož Turnšek (microbiologist), Sebastjan Kovač (biologist), Eva Jera Hanžek (artist), Anamari Hrup (artist), Altan Jurca (architect), Rok Oblak (designer ), Danica Sretenović (architect/curator), Gaja Pegan Nahtigal (eco-social design), Amadeja Smrekar (photographer)