If you wish to explore Vienna on your own (otherwise there are a number of guided tours), the best place to start the city center, with its museums, historical buildings and coffee houses.
- Near the conference venue
Central Vienna
Sights
Stephansdom [map]
The Gothic St. Stephan’s Cathedral with its multi-coloured tile roof and its grand tower is one of Vienna’s most recognisable symbols. The most important religious building in Austria’s capital and the seat of the Archbishop is located right in the center of the city.
(To go there: U1/U3 Stephansplatz)
Ringstraße
The Ringstraße is a circular boulevard surrounding the Innere Stadt district of Vienna (the historic city center). It was built in the 19th century, replacing the city’s medieval city wall. The boulevard is characterized by its many monumental and representative buildings, like the State Opera (built in the style of the Neo-Renaissance), the Parliament (Neoclassical style), City Hall (Gothic Revival), the Burgtheater (New Baroque), the Museum of Fine Arts and the Natural History Museum (Neo-Renaissance), and the Post Office Savings Bank (Art Nouveau). (To go there: U2: Schottentor, U1/U2/U4 Karlsplatz, or U3 Stubentor)
In 2015 the Ringstraße celebrates its 150th anniversary, and there are a number of exhibitions reflecting its history as well as a special tram going all the way around the Ringstraße.
Hofburg [map] 
The Hofburg Palace, the imperial residence in the centre of Vienna, is a complex of buildings spanning the centuries from medieval times to the end if the Austro-Hungarian Empire. There you can visit the Imperial Apartments and the Sisi Museum, the Imperial Treasury, or the baroque State Hall of the Austrian National Library.
(To go there: U3 Herrengasse or Trams 1/2/D Burgring)
Secession [map]
The Secession with its dome of golden laurel leaves is Vienna’s most striking example of Jugendstil (Art Nouveau) architecture. Built in 1897 as an exhibition space for the the "Association of Visual Artists Vienna Secession", it still houses exhibitions of contemporary art.
(To go there: U1/U2/U4 Karlsplatz)
Naschmarkt [map] 
Located near the Secession building Vienna’s largest market offers regional and international produce as well as a large variety of bars and restaurants and a weekly flea market on Saturdays.
(To go there: U1/U2/U4 Karlsplatz or U4 Kettenbrückengasse)
Museums
Museumsquartier
The Museumsquartier is a large ensemble of historical and contemporary buildings at the borders of Vienna’s Inner City, housing a number of art museums, restraurants, and shops.
MUMOK | Modern and contemporary art works | Museumsplatz 1, 1070 Wien (Museumsquartier) |
Kunsthalle Wien | Temporary exhibitions of contemporary international art | Museumsplatz 1, 1070 Wien (Museumsquartier) |
Leopold Museum | Modern Austrian art including key paintings and drawings by Egon Schiele and Gustav Klimt | Museumsplatz 1, 1070 Wien (Museumsquartier) |
Located across the street from the Museumsquartier are Vienna’s premier historical museums:
Kunsthistorisches Museum | Fine art, Egyptian, Near Eastern, Ancient Greek and Roman antiquities, sculpture and decorative arts, coins | Maria-Theresien-Platz, 1010 Wien |
Natural History Museum of Vienna | Natural history | Maria-Theresien-Platz, 1010 Wien |
Other Museums in the city center
Albertina | Features prints and drawings, graphic works, photographs and architectural drawings | Albertinaplatz 1, 1010 Wien |
Belvedere | includes two Baroque palaces, museum of Austrian art from the Middle Ages to the present, gardens | Prinz Eugen-Straße 27, 1030 Wien |
Haus der Musik | History of music | Seilerstätte 30, 1010 Vienna |
Sun - Fri 10:00 - 18:00 | Museum of Jewish history, life and religion in Austria | Dorotheergasse 11, 1010 Vienna |
MAK | Applied arts and contemporary art | Stubenring 5, 1010 Wien |
Near the Messe Congress Center
Prater [map]
The Prater is a recreational area in Vienna, but actually refers to two very different places: the Wurstelprater, an amusement park where the Riesenrad (Giant Ferris Wheel) is located, and an expansive public park called Grüner Prater (Green Prater).
(To go there: U1/U2 Praterstern, but you can walk from the conference venue.)
River Cruises [map] 
If you want to explore the city from the river, there is a departure point for Danube river cruises on the embankment near Reichsbrücke.
(To go there: U1 Vorgartenstraße, but from the conference venue it is quicker to walk.)
Other parts of Vienna
Sights
Schönbrunn [map] 
Schönbrunn Palace, once the summer residence of the imperial family, is a World Cultural Heritage site and Austria’s most visited sight. The rooms of baroque palace itself can be visited in guided tours, but you can also visit the vast palace gardens. 
There you can climb the hill to the Gloriette, which offers an excellent view of the city, or visit the Palm House, a 19th century green house.
Tiergarten Schönbrunn, the Vienna Zoo, is also part of the complex, having been founded as imperial menagerie in 1752.
(To go there: U4 Schönbrunn)
Museums
21er Haus | Austrian art of the twentieth and twenty-first century | Arsenalstraße 1, 1030 Vienna |
KunstHausWien | Features works by Friedensreich Hundertwasser and other exhibits | Untere Weißgerberstraße 13, 1030 Wien |
Sigmund Freud Museum | House, life and work of Sigmund Freud | Berggasse 19, 1090 Wien |