Salzburg is Austria's fourth largest city, and its second most visited after Vienna. A city has stood here since pre-Roman times, but Salzburg reached the height of its influence in the 16th and 17th centuries as an independent city-state under the rule of its Prince-Archbishops, and funded by profits from the salt trade (its name in German is literally "salt town"). Salzburg's influence waned in the 18th century, although every cloud has a silver lining and in Salzburg's case it was that many of the city's old buildings weren't destroyed in the name of "progress". As a result Salzburg boasts a well preserved Old Town, a UNESCO World Heritage sight, looking pretty much as it would have 300 years ago (only without the Japanese tourists), and its most impressive and visible monument, Hohensalzburg Castle. At the end of the Napoleonic wars Salzburg was incorporated into Austria, where it has stayed ever since.
Salzburg is also a city of music, from the sublime (Mozart was born here in 1756) to the ridiculous (the Sound of Music was filmed here).