Construction of the original Monastery of the Order of Teutonic Knights at Križanke have commenced in 1228. The earthquake of 1511 severely damaged the monastery buildings and they were partly rebuilt between 1567 and 1579. The original church was completely rebuilt in Baroque style between 1714 and 1715; it was designed by Venetian architect Domenico Rossi in a shape of a Greek cross, and was the first church of its kind in Slovenia. It has an ornate exterior and the gate area is accentuated with pilasters and a distinctive undulating dome. Slovene masters participated in the building process, including Gregor Maček, who designed the current city hall. The City Museum of Ljubljana keeps the original model of this church. The Knight's Hall was built during the 18th century.
Križanke continued to serve as a monastery until 1945, when the complex was nationalised. In 1952 representatives of the city of Ljubljana asked Jože Plečnik to remodel the now derelict monastery into a venue for Ljubljana Festival. The restoration and transformation of the monastery complex of the Holly Cross, vacated by the medieval German Order of the Knights of the Cross, was the last work of Plečnik in the 1950s. He completed respectable age of 80 while finishing the project. Plečnik proposed an open-air theatre within the abandoned monastery and so concluded his architectural program of creating a cultural artery on Vegova. He repaved the courtyard and added the frontage arcades in the shape of theatre boxes. The complex's original Gothic details were gradually subsumed by Renaissance and Baroque elements, as can be seen in the main courtyard, which features shallow archways and exuberantly-coloured sgraffiti. During the restoration he used old statues and portals from the ruins of Ljubljana buildings. Besides the open-air theatre he organized as well the smaller courtyard as an intimate archaeological garden with arcades and the Devil's Courtyard with its distinctively Mediterranean ambient.