Lovely Salzburg, 155 mi/240 km west of Vienna, is Austria's premier tourist city—it's as popular with Austrians as it is with visitors from the rest of the world. As a result, it can feel overrun with tourists during the summer high season—especially August. If you're going then, be prepared for long lines and dense crowds. (Don't even think about renting a car during this period—gridlock is the norm.) If you aren't put off by cold weather, a wintertime visit can be much more enjoyable.
Sightseeing
Most attractions in Salzburg proper are within walking distance of one another—easily within a half-mile/1 km of either bank of the Salzach River. On the west bank is the Altstadt (old town), characterized by plazas with statues and fountains and populated by baroque churches, well-known cafes, stores selling designer fashions, museums and souvenir shops. Though heavily tourist-oriented, it's rich in authentic atmosphere and detail—an outdoor market (mostly produce) flourishes on Universitatsplatz, and you can tour the narrow, cobblestoned streets of the area in a horse-drawn carriage.
To get oriented—historically and geographically—begin with a tour of Festung Hohensalzburg, the large white castle that looms on a cliff above the historic quarter; you can get there via a funicular railway or by taking a 20-minute walk. After taking a self-guided audio tour of the castle, you'll have a vivid understanding of life in medieval Salzburg. Next, investigate the Residenz, a palace that provides insight into the court life of the Hapsburgs. And after that, simply explore the streets, taking care not to miss Mozart's birthplace (which houses a surprisingly modest array of articles related to his life), Franziskanerkirche (a stunning baroque high altar and chapels) and the cemetery behind St. Peter's Church that contains catacombs. As you're strolling, keep an ear open for tunes played by the glockenspiel in the belfry of what is now a post office. If you haven't visited many classical European cathedrals, step inside the Dom (you can't miss the cathedral's twin green towers). Finish off the day with a meal or drink at one of Salzburg's local eateries or beer gardens. Or, listen to street performers play tunes on Mozartplatz.
The primary attraction on the other side of the river is Schloss Mirabell, a palace with gardens. Built for the mistress of a prince, it is now home to impressive gardens as well as a building (Zauberflotenhauschen) where Mozart's The Magic Flute was said to have been composed. Nearby are the Mozarteum, containing concert halls, and the Salzburg Marionette Theater, which performs—among other works—Mozart's operas. If you travel a little south of the Mozarteum, you can visit Mozart's Wohnhaus, where he lived for seven years (1773-80).
On the outskirts of the city is one of Salzburg's top attractions, Hellbrunn Castle. Its water gardens (operating only in the summer) are great fun, especially for children. When Archbishop Markus Sitticus built the place in the 1600s, he had trick fountains mounted in the floors and walls. To satisfy his quirky sense of humor, he occasionally sprayed his guests by activating a secret mechanism.
There are many other things to see and do in the area. Within a short drive in any direction are mountains, gardens and beautiful lakes (Traunsee, Wolfgangsee and Attersee are the best known). The view is spectacular from atop Untersberg's peak (6,022 ft/1,853 m), which is reached by cable car. Health spas and good downhill and cross-country skiing are available nearby. It's also possible to take tours just over the border into Bavaria in Germany.
Calendar
Some of Salzburg's annual festivals are Mozart Week (January); Fasching, or Carnival (beginning of February); the Easter Festival (March or April); Salzburger Festspiele (July to August); Jazzfest (October to November); and the Christmas Markets (December). The city truly comes alive during these times. Be sure to book hotel rooms far in advance (or stay in one of the many bed-and-breakfasts or private residences that are available outside the city).