These are: the Semmering Pass, the Pyrhn Pass, and the Tauern Pass. The roads leading through these passes are the most important lines of communication. The Pyrhn Pass is often used by tourists going on holiday to the Mediterranean Sea. The most important pass is the Brenner Pass, located on the Austrian-Italian border. It lies at an altitude of 1370 m and is one of the lowest Alpine passes. The road leads through the Inn Valley (the right tributary of the Danube) and is the most convenient connection between the countries north of the Alps and the south of Europe.