The Wasserwerk am Roten Tor is one of the oldest functioning urban water systems in the world. Tucked behind Augsburg's Red Gate, the ensemble of three medieval water towers and two Well Master Houses once kept the city's fountains flowing and its wealthy residents supplied, centuries before anyone had invented modern plumbing.

The oldest tower dates to the 1300s, standing 30 metres tall. Connecting to its pipes cost 200 guilders, at a time when an entire house in the lower town went for 60. The water pipes themselves were hollowed tree trunks joined with iron. Renaissance master builder Elias Holl later redesigned the Red Gate complex, and in the 1700s, Well Master Caspar Walter became so celebrated for his hydraulic engineering that specialists came from across Europe to study here. His initials are carved into the spiral staircase he built himself.

The whole ensemble is now a UNESCO World Heritage site. VoiceMap's self-guided audio tours trace how the canal system powered these works, explain the social hierarchy built into the price of water, and connect the towers to Augsburg's wider story as a city that turned engineering into civic pride.