Burg Dübelstein, Medieval castle ruin in Dübendorf, Switzerland.

Burg Dübelstein is a castle ruin in Dübendorf that sits on a flattened rock outcrop on the northeastern side of Adlisberg. The remains display thick walls and a circular defensive structure that still reveals its medieval form today.

The castle was built in the 13th century; a member of the Dübendorf family called himself Konrad von Dübelstein in 1257. In 1444 the Schwyzers devastated it, and it was rebuilt. In 1487 Zurich mayor Hans Waldmann bought it; after his execution it was plundered in 1489. On 27 May 1611 a maid drying flax started a fire that almost completely destroyed it, but the tower remained habitable.

The name Dübelstein first appears in 1257 as Tuobelnstein, borne by Konrad, a member of the family entrusted with oversight of Dübendorf. In 1889 the Waldmann-Ausstellungs-Komitee bought the site and made it a memorial to mayor Hans Waldmann; on 4 October 1891 it gave the hill to the city's burgher community. Since 1998 the hill has belonged to the Verein Pro Waldmannsburg, sold for one symbolic franc.

A path from the main road between Dübendorf and Fällanden leads to the ruins, with free parking available near the site. Access is straightforward and the location is open to visitors without any formalities needed.

Hans Waldmann, an influential Zurich mayor, acquired the castle in 1487, but was executed just years later. Following his execution in 1489, the fortress was plundered and lost its status as an important residence.