Slovakia, Hodrusa/Hamre, part Banska Hodrusa. The knocking tower was built in 1521 as a signal time and warning tower. Signals are till this time given from knocking to special shaped wooden board. This is one from 5 existing knocking towers on Slovakia (Kremnica, Banska Stiavnica, Spania Dolina by banska Bystrica and Solivar by Presov)