Hus, Castle ruin in the Bohemian Forest near Prachatice, Czech Republic

Hus is a medieval castle ruin in South Bohemia, Czech Republic, set on a wooded hill above a small stream. The remaining stone walls still give a clear sense of the original layout and the scale of the structure.

King John of Luxembourg authorised the brothers of Janovice to build a castle at Na husi in 1341 to protect their new villages around Záblatí. Charles IV confirmed the estate in 1359, and in 1363 it passed to the royal chamber. Wenceslas IV pledged it around 1390 to Zikmund Huler, executed in 1405; the castle was besieged and burned in 1441 and never rebuilt.

The castle's name is unrelated to Jan Hus the reformer: it comes from the rocky spur called Na husi, 'on the goose', where the castle was built. The Czech name Hus and the German Gans both mean 'goose'. The later owner Mikuláš of Pístný adopted the title 'of Hus' after the castle.

The ruin is freely accessible. A blue-marked hiking trail from Libínské Sedlo to Volary runs directly across the rocky spur through the remains. A marked path also leads to the ruin from the cemetery in the deserted village of Cudrovice.

The castle core is a so-called closed castle: collapsed masonry from the buildings filled the space between them and raised the ground level, so the original layout of the core is unclear. Two ditches and wall remnants survive in the high forest.