1KM of Urban Change - The Path to Transforming Prague´s Negrelli Viaduct into a Community Asset

Located in Prague’s Karlín neighborhood, the 1 km-long Negrelli Viaduct was a longtime site for illegal parking and garbage dumping. CCEA MOBA initiated the area’s revitalization, introducing the possibility of opening the arches for creative and local use. “1 KM of Urban Change” transforms the arches into vibrant spaces for residents and small businesses. This sustainable, community-driven project reconnects historic infrastructure with contemporary urban life and offers a model that can be used in the future to transform neglected spaces beneath transport infrastructure.

The Negrelli Viaduct project began after the State Railway’s 2012 renovation plans overlooked the space beneath its arches. Recognizing potential for renewal, the team united residents, NGOs, artists, and city and state institutions to reimagine the viaduct as a community asset. The first project, The Line Galleries (2013), developed with ten Prague galleries, showcased new possibilities for the site. In 2014, CCEA MOBA secured the transfer of land beneath the arches to the City of Prague– while the land under the pillars remained with the State Railway– a landmark success that created unprecedented conditions for public use and long-term access. Summer under the Viaduct (2016) tested future uses and deepened community ties, leading Prague’s City Council to accept the urban study and rent strategy, allocating 40% of spaces for commerce, 40% for creative activity, and 20% for artists and pop-ups. The 2024 Pilot Arch confirmed the model’s viability, establishing a replicable framework.

Constructed in 1849 from granite and sandstone, the Negrelli Viaduct is one of the longest technical structures from Europe’s 19th-century and Prague’s second-oldest bridge. Following a comprehensive structural renovation in 2019, the Pilot Arch project began. The self-standing structures feature aluminum façades, triple glazing, permeable stone bases for ventilation, and flexible joints to ensure resistance against train vibration and environmental wear. Traditional terrazzo flooring and locally sourced wood provide durability and regional authenticity. The interior conditions are navigated and monitored by the Klokner Institute at the Czech Technical University in Prague. The Pilot Arch tests both the technical and social conditions of the space, inviting different actors to trial for possible future uses. This modular approach minimizes maintenance costs and supports the scalable activation of 49 additional arches, merging preservation, functionality, and long-term sustainability.