Marschlins Castle, Medieval castle in Landquart, Switzerland

Marschlins Castle is a former moated castle on a flat plain about one kilometre northeast of Igis in the municipality of Landquart, Grisons. Its walls enclose a rectangle of roughly 34 by 39 metres, with three round corner towers 8.7 metres across and a larger corner donjon 11 metres across; the conical roofs are documented since the 17th century. Two moats surround it, drained as early as the 16th century and filled in on the west side, and access is from the west over a stone bridge probably built in the 17th century. Inside the walls the buildings ring a courtyard with a 17-metre-deep cistern.

The castle was first mentioned on 12 May 1324, when the knight Jacob von Marmels died before it. In 1336 the Bishop of Chur and Count Ulrich von Montfort disputed its ownership; the bishop prevailed and in 1337 granted it as a fief to Duke Albert II of Austria. In 1462 Duke Sigismund of Austria sold it to Ulrich von Brandis, who rebuilt it after a fire in 1460.

The Marschallstübli, built around 1633 under Ulysses von Salis, has carved panelling with marquetry, a coffered ceiling and a cocklestove from the Pfau workshop of Winterthur dated 1638. The Offiziersstube of 1638 is panelled in stone pine with the Salis coat of arms in the ceiling, and the Goldene Stübli of 1670 in the north-east tower has painted panelling and a ceiling with 43 constellations and the four winds.

The castle is private property and not open to visitors; it is seen from outside. It lies about 1 km northeast of Igis on flat ground, roughly 250 m from the right valley flank. Access is from the west over a stone bridge, probably built in the 17th century. The two moats are dry and filled in on the west side.

After the French invasion of Switzerland, the fortress was used as a military camp and then converted into a tobacco factory and silk spinning mill. This shift from defensive stronghold to industrial site shows how radically the building changed purpose over time.