Gräfsnäs castle, Stone castle ruins in Alingsås Municipality, Sweden

Gräfsnäs Castle is a ruin at the northern tip of Lake Anten in Västergötland. Its main building runs north-south with the main façade facing west, enclosed by deep moats and high ramparts. It had five towers and an arched entrance gate behind a moat, crossed by a drawbridge later replaced by a bridge.

The estate originally lay on the island of Loholmen in Lake Anten, where foundation walls remain. After peasants destroyed Loholm Castle, the widow of Sten Eriksson Leijonhufvud, Ebba Lilliehöök, moved the stronghold to the mainland in the mid-16th century. The castle burned in 1634, 1734 and 1834; after the last fire it was not rebuilt, and the roof was removed in the late 1880s.

The name Gräfsnäs echoes the title of Count (greve) held by the Leijonhufvud family, and the site remains linked to Margareta Eriksdotter Leijonhufvud, who according to tradition was born here before becoming Queen of Sweden in 1536. Since 2010 the castle park has been a municipal cultural reserve, and in 2022 SVT broadcast its Lucia morning service from the ruin.

The ruins are accessible by car, bus from Alingsås, or the vintage Anten-Gräfsnäs museum railway for a scenic journey. Parking is available at Wasaallén, and the grounds remain open year-round for exploration.

The castle burned three times, in 1634, 1734 and 1834, roughly a century apart. The roof was removed in the late 1880s, accelerating decay until the ruins were conserved in the 20th century. The site's park has been a municipal cultural reserve since 2010, and SVT broadcast its Lucia morning programme from the ruin in 2022.