Sychrov Castle, Medieval castle ruins in Rabštejn nad Střelou, Czech Republic

Sychrov Castle is a bergfrit-type ruin on the western edge of Rabštejn nad Střelou, about 480 m above sea level. Its rectangular core measures roughly 60 × 40 m, with a triangular forward platform, a wide ditch, and a palace site on the north side. The round bergfrit survives to about eight metres, with walls 2.7 m thick and a diameter of about seven metres.

Sychrov was probably founded under Charles IV by the Rabštejn burgrave Jindřich, who received the villages Kotaneč and Hrádek. It is first documented in 1439 as the seat of Jindřich of Rabštejn; his descendants held it until 1508, when Kryštof of Gutštejn acquired it. The king confiscated it the next year and attached it to Rabštejn; the Šlik family, who gained Rabštejn in 1518, left Sychrov to decay, and it was last mentioned as a castle in 1523.

The name Sychrov was also used as Hrádek, after the village the king granted to Jindřich of Rabštejn. The Šlik family, who acquired Rabštejn in 1518, left the castle to its fate, and it is last mentioned as a castle in 1523. The remains were long taken for an outwork of Rabštejn's town walls.

The ruins lie on the western edge of Rabštejn nad Střelou at about 480 m, separated from the Rabštejn castle by a natural hollow crossed by the road from Žihle to Stvoleny. The tower survives to roughly eight metres; its walls are 2.7 m thick and the core measures about 60 × 40 m.

The round bergfrit tower survives to the height of its first floor, about eight metres, with walls 2.7 metres thick and a diameter of roughly seven metres. Its original first-floor portal was walled up with rubble stone after the jambs were torn out.