The architecture of the 'Altstadt', or Old Town, consists largely of huge rows of houses, many of which date back to medieval times. Many of them are grouped around several smaller squares and alleys (Kälbernes Viertel). The Schlossberg, the City Park and the river Mur separate it from the rest of the city and moreover, UNESCO recently named this part of Graz a venue of 'World Cultural Heritage'. Apart from its historical and cultural significance, Old Town is also where many of the town's social life is played out. There are numerous restaurants such as the Restaurant Maroni) and cultural events such as the Steirischer Herbst. The city also gets very busy on Carnival Tuesday (Faschingsdienstag) and during the City Fair. On warm summer evenings it can be difficult to find your way through the masses of people, all of whom are looking for a free table at a café or a bar like the Mohrenwirt.