Four alleyways in downtown Chattanooga, Tennessee have been reclaimed and transformed into dynamic public spaces thanks to a community outreach project by AIA Tennessee and River City Company, the city’s economic development nonprofit .

Launched in August 2016, Passageways aims to highlight the potential of forgotten and unused spaces “by activating the urban alley through architecture:”

The purpose of Passageways is to re-imagine Chattanooga’s alleyways; to breathe life into these auxiliary spaces, to create a place, a destination in itself, and to demonstrate the value, the importance, and the potential of these between spaces and the significance they have to our built urban fabric.

The initiative put out an open call to architects, designers, engineers, and artists from around the world to create a public installation and event space within the narrow corridor between two buildings.

Five proposals were selected from 70 submissions. Two teams from Chattanooga, two from New York City, and one from Australia installed their winning projects in one week, transforming four alleyways found on the 700 blocks of Broad, Market, and Cherry Streets into interactive passageways that reclaim their historical purpose as a path for pedestrians and, as a byproduct, a hub of activity. But it’s the informal use of the alleyways that add the most color to the city.

Here’s a brief look at the winning installations. They are free and open to the public until the summer of 2017.

Stargaze, by Heavy, New York, NY

Through a network of interconnected light beacons suspended above and along the alley, Stargaze will utilize the Star API provided by NASA and the American Museum of Natural History’s Digital Universe Data to glow and mimic the night sky above for a contemplative and playful installation.

Grass Garden Inversion, by Team GFB, Chattanooga, Tennessee

Grass Garden Inversion is the suspension of locally sourced bamboo from high tension cables spanning the alley. The lower portion of bamboo hangs freely producing movement and sound. Creating a gathering spot unlike any other, added lighting will create dynamic shadowing at night.

Urban Chandelier, by Office Feuerman, Sydney, Australia

Forming Urban Chandelier, 850 individually CNC trimmed carbon fiber rods are suspended above the alleyway with 6,000 reflective styrene triangles precisely hung to reflect the natural day light and artificial night light creating visible light patterns. The material properties provide for ever-changing light effects based on available inputs; wind, direct light, reflections or even projections.

Stage Genies, by Art 120 and Studio Mindstride, Chattanooga, Tennessee

Through a connected and programmed network of cameras, speakers and computers, Stage Genies is a soundscape installation that tracks the movement of alleyway-goers and responds with music. Imagine walking through an alley and triggering the start of the beloved “Chattanooga Choo Choo” song.

Neural Alley by Revenge of the Electric Woman, Brooklyn, NY