Upper Castle Cistern
Before the 15th century, when the well in the middle castle was dug, the upper castle cistern had been used as the only water source for inhabitants of the castle site. The cistern was used for collecting rainwater which, in the event of a siege, had to be sufficient for all people in the castle. Water from the roofs was conducted into the cistern using the stone gutters discovered during the archaeological research of the site. The cistern was in a small courtyard which was also the lowest point of the upper castle.
From the construction point of view, an extremely precisely designed technological structure is concerned here. Thoroughly worked sand blocks attached to one another with tight joints were used for its construction. Leak-tightness was provided by the insulation layer of clay. The cistern with the diameter of 4.5m is 7m deep and is conically narrowing towards the neck trimmed with a stone curb. Ruts on the outer curb are remains of the structure with a pulley or shaft used for lifting up buckets with water.