In the early 1900s, Prague city officials commissioned a masonry embankment alongside the Vltava River. This was to protect against flooding and provide the structure for a quay. This massive wall was built with vaulted chambers within the wall, to be used as storage space.

In the 2010s, these historic vaults were turned into contemporary businesses under a design by architect Petr Janda. The vaulted spaces were given massive acrylic portholes on a pivot, to serve as their entrances. Of these businesses, perhaps the best known today is the (A)Void Café. Its striking entranceway has become a social media destination:

Cool aesthetic aside, the risk remains. The Vltava last flooded in 2002, and the café had to temporarily shut down in September 2024 when the river threatened to (but did not ultimately) flood. Get your visit in before climate change accelerates.