In the middle of the Town Hall Square, in the center of the circular town plan, is the Town Hall, built in 1798 according to Johan Brockman's drawings. The Town Hall has changed its shape several times due to the three big fires that raged in the 19th century. After the fire of 1840, it was repaired to its current Empire style. The four bells in its tower are installed by Johan Könni the younger in the 1840s.

During its history, the Town Hall has been housing a bank, police stations, shops and a museum. Both the Swedish and the Orthodox congregations have also temporarily operated there. The Town Hall was extensively renovated from 1987 onward, and it was opened again in the summer of 1996. Since then, the building has been the venue for the city council and the city government meetings.