Salzburg is the fourth-largest city in Austria and the capital of the federal state of Salzburg. Salzburg's "Old Town" (Altstadt) with its world famous baroque architecture is one of the best-preserved city centres north of the Alps, and was listed as a UNESCO World Heritage Site in 1997. The city is noted for its Alpine setting. It is the birthplace of 18th-century composer Wolfgang Amadeus Mozart. In the mid-20th century, the city was the setting for parts of the musical and film The Sound of Music, which also features famous landmarks in Austria. With three universities, Salzburg is filled with the liveliness of a large student population.