Burg Hochhaus, Medieval castle in Hohenaltheim, Germany.

Burg Hochhaus is a fortified castle on a hilltop near the Kartäusertal valley in Bavaria, built of stone with towers and defensive walls that overlook the surrounding land. The site comprises multiple building structures arranged across the grounds and demonstrates the defensive characteristics of a medieval noble residence.

Burg Hochhaus was probably founded around 1200 as the seat of a branch of the free noble family of Hürnheim, which then named itself after the castle (de alta domo). Rudolf I von Hochhaus appears as a witness in a charter of 1236. In 1347 Konrad II sold the site for 3000 pounds to the counts of Oettingen-Oettingen, who used it as an administrative seat and modernised its defences in the 15th and 16th centuries. In 1719 the complex was converted into a Schloss, which burned down in 1749 and was not rebuilt.

The castle shapes the landscape through its heavy walls and towers that stand distinctly against the surrounding terrain. Visitors experience during exploration how medieval construction was adapted to the natural topography of the region.

The ruin is at risk of collapse, so keep to the outside and do not enter the walls; major parts of the structure can be viewed from outside. It stands on the Hochhauser Berg at 555.2 m above sea level, about one kilometre from the neighbouring Niederhaus castle, above the Kartäusertal valley on the edge of the Ries crater. No maintenance work on the masonry is recorded apart from the securing of the counterscarp of the neck ditch in the 1960s, which has already partly collapsed again.

The fortification sits at the edge of the Ries crater, one of Europe's largest visible meteorite impact sites. This geological feature shaped the landscape and possibly influenced the choice of location for the fortress.