Piast Tower, Gothic defense tower in Opole, Poland.

Piast Tower is a round, free-standing brick tower in the south-eastern corner of the former Piast Castle in Opole. Its walls are up to 3 m thick at the base, set on a 6 m deep fieldstone foundation. The tower rises 42 m to the top of its 1957 helm, or 51 m including the spire and Piast eagle weathervane.

Built around 1300 under Duke Bolko I as the keep of Opole Castle, the tower was first entered at a height of 9 m via a wooden gallery. It survived the town fire of 1615, but a 1739 blaze destroyed its original conical helm. In 1928 the castle was demolished and the tower was incorporated into the regional government building.

Locals nicknamed the tower "Proskespargel" after the Prussian official Prosk e, comparing its slender form to asparagus. The name Piast Tower recalls the Silesian Piast dukes, and the weather vane on the spire carries the Piast eagle, a detail visible from the viewing platform.

The tower is open to visitors who wish to climb its interior, though the steep stairs demand reasonable physical fitness. Plan your visit in advance by checking local conditions and availability, as access may be restricted to organized visits.

The tower leans about 1.5 degrees because its foundations settled unevenly, a tilt visitors can notice when comparing it with the vertical facade of the neighbouring Voivodeship Office. Its 162 steps lead up to the viewing platform, and the original entrance was an opening 9 m above ground, reached by a wooden gallery from the castle walls and now walled up.