Ursulinska cerkev svete Trojice (Ursuline Church of the Holy Trinity), Ljubljana

Much like the Church of the Annunciation shapes Prešeren Square, the Baroque-style Church of the Holy Trinity serves as the grand conclusion to Congress Square, distinguished by its unique facade. Built in the 1720s under the guidance of architect Carlo Martinuzzi, who drew inspiration from the designs of renowned Roman architect Francesco Borromini, the church boasts a magnificent baroque interior, crowned by Francesco Robba's exquisite high altar crafted from African marble. The original bell tower succumbed to the earthquake of 1895, but a faithful replica was erected in the early 1900s. Notably, architect Jože Plečnik contributed to the design of the staircase leading to the entrance in 1930.

Facing the church is the Holy Trinity Column, initially constructed from wood but replaced with stone in 1722 by Luka Mislej, with marble statues presumably crafted by Francesco Robba. In 1834, stonemason Ignacij Toman fashioned a new pedestal, and a replica of Robba's sculpture replaced the original, which is now housed in the City Museum of Ljubljana. After the 1895 earthquake, the column underwent renovations and was relocated to its current position in front of the Ursuline Church in 1927, as part of Plečnik's redesign of Congress Square. It now forms an axis with the Ursuline Church, the square's lighting, and the Slovenian Philharmonic building.