Linz is a Danube River cruise por in Austria, also the country's 3rd-largest city (after Vienna and Graz) and the capital of the state Upper Austria. The city is approx 30 km (20 mi) south of the Austria-Czech Republic border. Its population is around 195,000. The city is also known worldwide for the Linzer torte - the world's oldest cake. Its recipe dates from 1653.
Among the Linz' landmarks and attractions are Landstrasse (main street), the Schloss castle, St Martins Church (the Austria's oldest), Mariendom (St Mary's Cathedral), Pöstlingberg-Kirche: (Postlingberg hill), Brucknerhaus (concert hall), Gugl Stadium, Linzer Landestheater, Musiktheater, Lentos Art Museum, Donaulande (aka Kulturmeile, river park), Freiberg park, Wasserwald park, Linzer Zoo, Nordico (City Museum, arts, historical and archeological artifacts), Oberosterreichisches Landesmuseum (regional history), Oberosterrreischisches Literaturmuseum (of literature), Zahnmuseum (dentistry equipment), Fatsy (Cowboy-Museum), Botanischer Garten, Ars Electronica Festival, International Brucknerfest
Linz is also the cruise port to Mauthausen - a market town located approx 20 km (12 mi) to the east. On the hill above the town is the Nazi concentration camp that was the main camp of ~100 subcamps throughout Austria and Germany.