The Alte Wasserkunst is the squat round tower at the south-western corner of the old town, dropping straight down to the Spree. Built in 1558 by the Saxon engineer Wenzel Röhrscheidt, it pumped river water up to the higher town and supplied Bautzen for the next four centuries — an unusually long run for any piece of pre-industrial infrastructure.
The interior houses a small museum on the history of the city's water supply, and the climb up the staircase to the open viewing platform on top gives the postcard view back to the Petridom and the old town. The pump machinery has been preserved in working order. Open daily from spring to autumn.