Hinkelsturm, Medieval defense tower in Darmstadt, Germany.

The Hinkelsturm is a roughly 16-metre-high tower rebuilt from natural stone, standing within Darmstadt's double city wall. It has a square plan with 5.3-metre sides and three stacked rooms of just under 4 by 4 metres, reached by metal stairs and internal steps. A wide glass roof projects around its top.

The Hinkelsturm is a natural-stone tower rebuilt within Darmstadt's double city wall, which runs roughly north to south; it stands in the western part of that wall. The Altstadtmuseum opened in it in 1997, after the first sod was turned in July 1994 and rubble was cleared from between the walls on Lindenhofstraße. It succeeded the city museum destroyed in the September 1944 air raid. The museum was financed by donations, about 1 million DM without municipal funds.

The tower is named after the Darmstadt Hinkelstein, a nearby stone. The museum opened in 1997 and is run by the Heimatverein Darmstadtia e.V., which took over from the Freundeskreis Stadtmuseum Darmstadt in 2020. The old town model by Christian Häussler was presented at the opening; four relief panels showing the old town around 1850 are set into the pavement in front of the museum on Lindenhofstraße.

The tower requires climbing narrow stairs to reach the upper floors, so wear comfortable shoes and be prepared for a workout. Arrive early as the small space inside can get crowded during visiting hours.

The tower's name comes not from the tower itself but from the Hinkelstein, a stone standing nearby in Darmstadt. The museum opened in 1997 and, measured per square metre, drew more visitors than the Deutsches Museum in Munich. Its roughly 1 million DM cost was raised through donations, without municipal funds.