In 2021, the Croatian Conservation Institute conducted multidisciplinary conservation-restauration and archaeological research in the northern courtyard of Banski dvori Palace to determine the layers of historical development. The results confirmed the continuity of settlement of the Zagreb upper town plateau from prehistoric times to the present day, and served as a basis for the development of project-technical documentation required for the complete restoration of the Government of the Republic of Croatia building damaged by the 2020 earthquake. During the excavations, remains of a subterranean timber-framed structure were documented. Based on the archaeological finds and context it can be interpreted as the underground storage room of a medieval urban house dated to the period of 13th and 14th century. A total of 1464 plant macrofossils were isolated by archaeobotanical analysis, of which six were carbonized and some of remains were just partially mineralized. The majority of the finds (95%) represent woody edible species with the highest number of finds being grapevine (Vitis vinifera), sweet/sour cherry (Prunus avium/cerasus), and blackthorn (Prunus spinosa). Some woody species such as grapevine and peach (Prunus persica) were certainly cultivated, while others like Cornelian cherry (Cornus mas) and blackthorn are evidence that the population collected fruits from nature. Edible herbaceous species accounted for 2.12% of the finds, included cucumber (Cucumis sativus), spice fennel (Foeniculum vulgare), cereals millet (Panicum miliaceum) and common wheat (Triticum aestivum/durum). More than 40% of the remains were found in five vessels, while the rest were from the surrounding sediment. All vessels contained grapevine and wild apples/pears, and fruits such as sweet/sour cherry, blackberry and plum were also found, leading to the assumption that the vessels contained the commonly used medieval beverage made from unripe fruit, known as verjuice.