St. Nicholas's Cathedral is located in the namesake square. Inside are preserved the relic of the Sacred Hair and an icon of the Madonna of the Letter. The building is in neo-Romanesque: the salient facade has a small portico with four columns and three entrances, the main one is located on a rose, while on either side, two single windows. The interior has a Latin cross plant, with three naves separated by two rows of eight Doric columns square each, which support round arches. At the transept, two naves consecrated to St. Nicholas, patron Saint of the city, and to the Sacred Heart. The ceiling of the nave is vaulted, while the coverage at the crossing consists of an octagonal dome without openings. To the right of the presbytery is the Chapel of the Sacred Hair. Outside the building, on the left, the Clock Tower serves as a bell tower of the Cathedral itself.