One of the most beautiful buildings on the square is the Renaissance house from 1563 called the Old Post Office, which is characterized by two arcades. It is this house that testifies to the wealth of Nový Jičín's mayor and its builder Ondřej Řepa, who originally intended to move the arcades to the opposite side of the courtyard. However, the Italian builders he invited to build it turned them behind the sun, on the square. Between 1787 and 1852, the hereditary post office operated here. Its guests included the famous General A. V. Suvorov and even the Russian Tsar Alexander I. The reconstruction of the late 1970s rehabilitated the building and created office space in the attic. The building is fully basemented. The vaults are partly late Gothic, Renaissance and Baroque.

Nowadays the Old Post Office building houses the Municipal Cultural Centre and hosts exhibitions and other cultural events.