Lower Austria is a federal state on the northeast of the Republic of Austria, centered around Vienna, with the city being a part of the state until 31 December 1921. On 10 July 1986 Lower Austria chose Sankt Pölten for its capital city, where the State Assembly of Lower Austria started to hold its sessions in 1997. The entire region is traversed from west to east by the mighty European river of Danube. The north-eastern section of Lower Austria is mostly a rolling country combined with lowlands, while the north-west is typical of prevailing highlands. The south of Lower Austria is dominated by the Alps, a mountain system reaching up to 2,000 m above sea level where the region borders Styria. Wines from vineyards stretching alongside the Danube river count among the World's best, and the quality viticulture encountered between the counties of Wachau and Carnuntum have developed the area into a gastronomic paradise. The region boasts a variety of chateaux, medieval castles, baroque monasteries and a good many towns and forts of Roman origin. Even today the Danube is a busy traffic route: especially attractive are boat trips through the UNESCO listed Wachau region and bike trips up and down the cycle path along the river, in fact the most popular such path in Central Europe.