During the exploration of the underground in Česká Street, a probe placed in front of the facade of the former perfume shop called Convalaria discovered a small medieval cellar with an access corridor. On the clay floor, a small well with brickwork was found in the middle of the room under a layer of clay. The well body even contained a well-pumping device, which was still quite preserved.
The discovered late Gothic cellar was built in the second half of the 15th century. The relatively small building is made of stone and mixed masonry and is vaulted with a brick arch. It is situated less than two metres below street level, between two trees, directly in front of the glass window of the present café. The access passage to the cellar from the south was probably formerly connected to another cellar, which disappeared with the construction of the present house. The cellar was probably used as a storage space and later as access to the well. The latter is very special. It is about 4 m deep from the level of the brick-paved floor and is still active. Its timbering is interesting, which was made of brick, tile and stone. Its metre diameter changes from circular to square and back to circular as it gets deeper.
The discovered cellar could not be connected to the existing building, so the entrance was built on the opposite side. A vaulted opening was built in the head of the Gothic wall and connected to the newly created entrance shaft. The well was fitted with a grille, and the found pump was handed over to the Technical Museum by archaeologists. Today, the cellar can only be entered through a cast-iron hatch set in the pavement. In the summer gardens of the neighbouring restaurants, few people notice this entrance.