After the foundation of New Town in Prague in 1348, Charles Square was defined as the centre of its southern part. It was originally called Large Market, New Town Square or the Square of the Upper Town, from the 15th century until 1848 it was known as Cattle Square, and since 1848 it has been called Charles Square (after Charles IV, the founder of New Town). Its present appearance was defined by the park founded in 1866, further modified by the garden architect František Thomayer in 1884.
During the war, an air raid water reservoir was built in the northern part of the square as part of the preventive measures organised against expected bombing. The capital was an important communication and industrial centre (a number of military factories were there), however, the air raids avoided Prague until 1944. Although the local population considered all the preventive measures useless, the German authorities did not neglect the preparations. In addition to wooden casings, shelters and preventive buildings, 67 water reservoirs were built in Prague, often causing damage to historic squares and parks. Such reservoirs could also be found, for example, on Old Town Square, Lesser Town Square, Hradčanský and Bethlehem Square, in Peace Square, in Svatopluk Čech Park, in the Franciscan and Loretta Gardens, in front of Prague City Museum or at the bottom of Vitkov Hill near today's Army Museum. Some of the tanks were filled in after the war, others turned into park ponds.
Josef Sudek, when photographing Prague, was drawn to several tanks in the historical centre of Prague. He documented the reservoir in the northern part of Charles Square, with its dominant feature the New Town Hall, which was established in the years 1377–1398 as the administrative center of New Town. Its current appearance dates to 1905 and is the work of architects Kamil Hilbert and Antonín Wiehl.