Main entrance to the Schönbrunn Palace and Gardens, one of the major tourist attractions in Vienna (locals use the Gardens for jogging and walking, but never enter the Castle itself ;).
Schönbrunn can be reached by the U4 underground (stop "Schönbrunn" for the castle, or stop "Hietzing" for the zoo). Limited (and pricey!) parking available - use public transport if possible!
There's a lovely Christmas market in front of the Castle from mid of November until 24th of december.