For the first time it was mentioned under the name of the Sand Tower. At the beginning of the 14 century the tower was a main part of Sand Gate fortification system, consisting of 25 towers. It stood on the Sand Road that led to the town. From the 17th century the Powder Tower served as a gunpowder warehouse. So it gained the name "Pulvertornis" meaning Powder Tower in English. It had to stand main attacks of Swedish troops in 1625 and was restored only in 25 years. The war with Russia left its traces too. 9 cannon balls embedded in its thick three meters wide walls. Today in the Powder Tower the Latvian War Museum is located. The museum was founded in 1916 as the Latvian Riflemen's Museum. In 1937-1939 a new museum extension was added to the Powder Tower. The museum was closed by Soviet authorities in 1940 and reopened in 1990. The museum houses the permanent exhibitions "Latvian Soldiers During World War I 1914-1918", "Proclamation of the Latvian State and Liberation Battles 1918-1920", "The Latvian Army and Navy 1919-1940", "Latvia and World War II" and "The Road towards the Barricades 1945-1991".