Four days is enough to see the essence of imperial Vienna without exhausting yourself, provided you group the sights geographically instead of zig-zagging across the city. Here's a tested itinerary that spreads the four major landmarks across sensible days.
Day 1: The Old Town (Innere Stadt). Start the morning at St. Stephen's Cathedral (Stephansdom), Vienna's symbol, whose foundation stone was laid in 1359. The cathedral is open daily from 6am to 10pm (Sundays and holidays from 7am), but the paid interior section is only accessible from 9–11:30am and 1–4:30pm, since it closes for services. Climb the South Tower (137 meters, once the tallest building in Europe when completed in 1433) for a panoramic view. In the afternoon, wander Graben and Kärntner Straße nearby, then ride tram D, 1, or 2 along the Ringstrasse — the boulevard Emperor Franz Joseph built in 1857 on the site of the old city walls, passing the Parliament, the State Opera, and the Natural History and Art History Museums.
Day 2: The Hofburg. This was the Habsburg dynasty's winter residence for over six centuries. Give it a full day covering three sections: the Sisi Museum (dedicated to the famous Empress Elisabeth), the Imperial Apartments, and, if you're interested, the Imperial Treasury. The Sisi Museum is open daily from 10am to 5pm (last entry 4:30pm). The combined "Sisi Ticket" (Schönbrunn + Sisi Museum + Imperial Apartments) costs €57 for adults and €37 for children (6–18), saving you from buying separate tickets. Book online in advance to skip long queues, especially in summer.
Day 3: Schönbrunn Palace. Vienna's grandest palace, a UNESCO World Heritage site, and Franz Joseph's own birthplace. It opens daily at 6:30am, with closing times varying by season: 5:30pm in winter, 7pm from March to October, 8pm in April, August, and September, and 9pm from May to July. The basic Imperial Apartments tour (about 25 rooms with audio guide) costs around €28, and the Grand Tour (about 40 rooms) around €38. Don't skip the free-to-enter palace gardens, the Palm House and butterfly house, the maze, and the climb up to the Gloriette on the hill for a picture-worthy view. If the weather is good, budget an extra half-day just for the gardens.
Day 4: A flexible day. Use it for one of two options depending on your interest: visit the Belvedere Palace to see Klimt's "The Kiss," or go shopping on Mariahilfer Straße and at the Naschmarkt (see our dedicated shopping guide). If you're traveling with family, consider a day at Prater park and the famous Riesenrad Ferris wheel instead (see our family guide).
Practical tips. Buy a Vienna City Card if you'll visit 3 or more paid attractions — the cumulative discounts add up on top of the transport benefit. Schedule days 2 and 3 to avoid overlapping with crowds; early mornings are always calmer. Most Old Town sights are walkable, but Schönbrunn requires the metro (U4 line, Schönbrunn station) since it sits slightly outside the center. Bring a water bottle and comfortable shoes — Vienna rewards walking as much as it rewards riding the tram.