The square, or as it had been said earlier the market-place, was originally called At the Splash. Or Place of the Mother of God, or Marian Place. It was because there was old settlement At the Splash with Romanesque church of the Virgin Mary, which has been demolished nowadays. Name of the settlement was related to the fact that near river Vltava leaked water through its natural banks in each big flood and then splashes were remaining there. Since 19th century the verbal form of Marian Square had been used. Since 1952 the name Square of Mayor dr. Václav Vacek was valid. The aforementioned was a long-time officer of KSČ and during 1945-1954 he was the mayor of the capital of Prague. New street name plate with historical name Marian Square was fixed by the Prague mayor of that time, Jaroslav Kořán, by himself on 26th June 1990.
Clementinum no. 190 turns into the Marian Square with its eastern front. The dominant feature is the New Town Hall – City council of Prague, a late art-nouveau building from 1908-1911 according to design by arch. Osvald Polívka. The mayor and other authorities have their seats there. In the corner alcoves of the front there are standing sculptures representing rabbi Löw – Jehuda Liva ben Becalel and the Iron Knight, pieces of art by sculptor Ladislav Šaloun from 1908-1910.
The northern frontage of the square is formed by front of the Municipal Library no. 98. Construction was realized according to designs by arch. František Roith during 1926-1930.
The southern side of the square is formed by outer wall of Clam-Gallas Palace. In the wall there is mounted a fountain with female figure, an allegory of Vltava, popularly called Terezka. The sculpture was made by Václav Prachner in 1818.