Ljubljana Cathedral — officially the Church of St Nicholas — stands at Vodnik Square just east of the Triple Bridge. The current building dates from 1707, replacing an earlier Gothic church on the same site. The twin towers are visible from all over the old town. The interior is decorated with elaborate frescoes and Baroque altars; the oval dome fresco by Giulio Quaglio depicts the ceiling of heaven populated by Slovenian bishops and saints.
The cathedral is the seat of the Archbishop of Ljubljana and functions as an active church. It is open to visitors throughout the day; enter through the side door when a service is in progress.