Centuries ago, the citizens of Gera created a veritable labyrinth under the houses in the old town to store beer. The corridors, niches and vaults, which are up to eleven meters deep, are known as "Höhler". Ten of these unique testimonies to Gera's economic and commercial life have been linked together and can be visited on public tours or by appointment. During the tour, visitors learn interesting facts about brewing and selling beer in the old days, about the construction of the caves and their later use.