A recommended travel itinerary for Vienna, Austria could include:

Day 1:

• Explore the historic center and see St. Stephen's Cathedral

• Visit the famous Ringstrasse, a street that circles the center of the city

• Stop by the State Opera House

Day 2:

• Visit the Palace of Schönbrunn, the former summer residence of the Habsburg emperors

• Take a stroll in the Schönbrunn Park, the oldest Zoo in the world

• Explore the Museumsquartier, a cultural area with museums and exhibitions

Day 3:

• Visit the Kunsthistorisches Museum, which has an impressive collection of art and artifacts from around the world

• Explore the Natural History Museum, which showcases the history of the Earth and life on it

• Take a walk along the Danube Canal and stop by the trendy areas of Spittelberg and Neubau

Day 4:

• Visit the Belvedere Palace and its baroque gardens

• Walk through the charming streets of the Grinzing wine-growing village

• End the day with a visit to the famous Viennese coffeehouses

These are just some suggestions, and the itinerary can be adjusted according to personal preferences and time available.