The castle, which formed part of the Vicarage of Corzes/Kortsch, was ceded as part of a feudal exchange by the Diocese of Frisinga to the Bavarian Counts of Moosburg. Today, all that remains is a tower with frescoes.
On the eastern edge of the small village of Lasa are the remains of a medieval residence. Of the original building, only a square residential tower with an edge length of 5.2 metres and a wall thickness of 0.65 metres has survived, which on its eastern side has the remains of a coat of arms fresco (royal eagle and golden fleece and four small coats of arms, shield, Tyrol, Austria, Burgundy and the year 1497) and whose defensive plate is crowned by swallowtail battlements. It was later integrated into a complex of buildings. On the opposite, northern side of the street stands an old residential building, which was apparently connected to the residential tower for a long time and formed a unit of ownership with it. Perhaps it was even connected to the tower by a wooden bridge on the upper floor.
Different statements exist about the name of the estate. While the residential tower is almost unanimously named Eyrsburg, the term Moosburg is used either for the opposite residential building, for the complex of tower and residential building, but also as an alternative to Eyrsburg.