Gruber Palace, which currently houses the National Archives of Slovenia (Narodni arhiv Slovenije), was built between 1773 and 1781 to designs by the Jesuit Gabriel Gruber, best known as the engineer who changed the appearance of Ljubljana by building the Gruberjev kanal drainage channel. Gruber Palace, which includes an astronomical observatory, was designed for the purposes of Gruber's School of Hydraulics and Mechanics.

The Palace is of the late Baroque style. Skilled stucco workers were commissioned to decorate its façade and interior with characteristic Zopfstil flower braids. The interior boasts a well worth seeing oval staircase topped with a domed ceiling.

The first floor houses a chapel painted with scenes from the life of the Virgin Mary. The paintings, dating from 1777, are by the Austrian painter Johann Martin Schmidt, also known as Kremser Schmidt. The slightly time-darkened allegorical paintings of Commerce, Handicraft and Technology on the domed ceiling above the staircase were created by the Ljubljana-based painter Andrej Janez Herrlein in 1786, two years after Gruber's forced deportation to Russia.