One of medieval Riga's fortification wall towers, originally called the Sand Tower. Built in 1330.
Reconstructed several times, and in the 17th century it was named the Powder Tower due to gunpowder stored there. Its present appearance was set in 1650. In 1919 the War Museum was established in it. In 1937–1939, an annex building was added according to a project by architect A. Galindoms, now this part hosts large and various exhibitions. The height of the tower is 25.6 metres, diameter — 14.3 metres and wall thickness — 3 metres.