Lina, Fortified house ruins in Vrbička, Czech Republic.

Lina is the ruins of a fortified house in Vrbička built from stone and positioned on elevated ground. The remaining wall sections reveal the basic layout of this medieval structure with components designed for defense.

No written record of the site survives, and its original name and purpose are unknown. Pottery found on the Linaberg dates from the 14th and 15th centuries, and the ruin may have been the seat of Beneš of Kolowrat, mentioned in 1531 as owner of the Vrbička estate. It has been a protected cultural monument since 1958.

The name Lina comes from the German name of a nearby manorial sheepfold, Lihna; the ruin's original name is unknown. Franz Alexander Heber first described and drew it in 1844, while August Sedláček later proposed the name Hrádek u Valče. Since 1958 it has been protected as a cultural monument.

The ruins lie 1.5 km northwest of Vrbička on the Lina hill (520 m), above the overgrown Linateich pond; a forest path leads southeast from the Ořkov lodge on the road between Nová Ves and Valeč, and another path comes from the Hlína sheepfold. The site is within the Jalovcové stráně nad Vrbičkou nature monument, and no archaeological excavation has yet taken place.

The ruin is not a castle: castle researcher Tomáš Durdík noted that almost all typical castle elements are missing and the walls are only 1.2 m thick, so the site resembles a fortified settlement or a large farmstead. The rectangular stone torso measures 7.1 × 7.9 m and stands about 3 m high.