The visual apex of Muntplein (Mint Square) is Munttoren. The original tower was built in 1487 as part of a city gate (Regulierspoort). After a fire in 1618, the tower was rebuilt. In 1672, during the French invasion known as Rampjaar (Disaster Year), coinage was temporarily minted in the adjacent guard house, hence the name Mint Tower. Above the four clocks is a carillon of 38 bells. 13 of them were cast in 1651 by master bellfounders Pieter and François Hemony. Munttoren has free concert of the bells on Saturdays at 2:00.