The Hofburg eats up about half of the space within the ring road. It's a sprawling mass of buildings that together made up the Hapsburg's palace. The place grew haphazardly over the centuries, and in fact these four photos don't really seem to be of the same place, but they're all just various parts of the maze the family lived in.

That giant arc in top left in fact was built just a few years before World War I, which saw the end of the Hapsburgs as rulers. At top right were the Imperial stables, now the famous Spanish Riding School, which still teaches some very lucky horses to dance around in precision. Not high on my to do list, but it's a big tourist draw, for better or worse closed while we were there. Much of the palace is open for tourists, or converted into museums. The imperial library is a must see as well, an out of this world baroque interior with a stunning collection.