This cool looking photo was taken on Dec 15 in 2025 by Jens Kastner, who is based in Frankfurt, Germany. His photo is an example of one of thousands of khaki-colored mouse shelters that crisscrossed the German countryside. These places, originally built to train soldiers for World War II, now serve many different uses and they’re doing so in fascinating ways.
Germany has a large stock of air raid shelters. Most of these structures have been adapted and reused to better serve the evolving needs of urban society. Through her art, Kastner reminds us of these spaces’ historical importance. More importantly, it highlights inspiring examples of how communities have welcomed them back, after being neglected for decades.
Over the past few years, many of these shelters have experienced striking changes for the better. The lucky few have become techno rave venues. These venues are a can’t-miss experience for any music lover looking to catch the underground before they blow up. The cold, unadorned design of the shelters is a world away from the seductive intimacy of a nightclub. Together with podcasts, these two mediums make for a unique engaging experience for the participants.
Other air raid shelters have been converted into climbing parks. Adventure seekers have a stunning new, unconventional playground to embrace their pursuits of health and happiness. This creative reuse not only offers promise in preserving these historic structures but provokes positive interaction among community members and healthy recreation.
Kastner’s photography serves as a visual narrative of Frankfurt’s architectural evolution. In documenting these sites, he challenges us to remember their history by grappling with what they are today—artifacts of a complicated and layered history. Yet their cultural significance today couldn’t be more different, as the current American zeitgeist would suggest. This interplay produces an intriguing critique of gentrification, and the stranglehold time holds over urban spaces.
From Amsterdam to Sydney, cities around the globe are creatively reclaiming unproductive areas. Germany’s zaunhäuser, or mouse-colored air raid shelters, are some of the most impressive examples of guerrilla urbanism and creativity on this front. They represent a spirit of innovation and change, demonstrating that communities can respect their storied past while still welcoming the present and the future.