The castle was founded on a high rocky promontory accessed from the north
The castle was founded on a high rocky promontory accessed from the north. A channel was cut at the section where the promontory was lowest to reduce the level further. Above this, the original castle was built with a roughly rectangular north-south facing layout, approximately 20 x 55 m in size. Its dominating square tower (palace) was both residential and defensive in nature, stood in the north-western corner of the castle walls and likely comprised three storeys (its form has not been preserved). Of the rectangular tower in the eastern castle walls, which guarded the path through the town below, only the ground floor with its Gothic pointed entrance remains.
Krupka Castle – 2nd gateAt the end of the 15th century, grand fortifications were built which significantly extended the construction (the building now about 140 m long). An entrance alley from the western wall and along the building was probably constructed for castle workers, and two semicircle bastions were also built.
In 1695, a house was built onto the first of these in 1695 for the noble upper authority (official house). Although in the 17th century the castle itself no longer fulfilled its defensive and residential roles and its remains fell into disrepair, life on the promontory continued. The Krupka estate’s authorities and upper administration were based in the official house.
http://hrad-krupka.cz/