Schwammerlturm, Leoben, Medieval gate tower in Leoben, Austria

The Schwammerlturm is a roughly 30-metre-high medieval gate tower in Leoben, the only surviving city gate and the town's landmark. Its eight-sided dome roof, cut in semicircles at the lower edge for four clocks, overhangs the narrower top storey like a mushroom cap. A narrow one-way road passage runs through the tower, with pedestrian passages alongside.

A fortification guarding the western entrance to Leoben was built when the settlement was relocated in the 13th century, possibly after a fire in Alt-Leoben in 1268. The medieval structure was renewed in 1512 and rebuilt from the ground up by Peter Carlone in 1615. After the 1794 earthquake loosened four oriel windows from the masonry, the tower received its dome roof.

The tower's everyday name comes from its dome, which overhangs the narrower top floor like a mushroom cap (Schwammerl). On the outer side an inscription in verse recounts the tower's history, its last two lines added by Josef Freudenthaler in 1954; the inner side bears the Leoben coat of arms and the Austrian federal emblem. Since 2016 a staircase display shows 28 reproductions of paintings of the tower from 1890 to 1985, and during Advent the Turmblasen brass concerts take place.

The café and its terrace sit in the top storey, reached from the ground floor by 119 steps; a lift replaces about two thirds of the climb, starting after 15 glass steps and 25 steps in the neighbouring building. Pedestrians pass on both sides of the gate tower through the adjoining buildings, while the roadway under the arch is one-way eastbound.

The nickname arose after the earthquake of 1794: four oriel turrets had come loose from the masonry above the roof truss, and the pointed roof was replaced by a dome, giving the tower its mushroom shape. Its real name, Mautturm (toll tower), is rarely used today.