The Potala Palace: Tibet's greatest monumental structure
Mont Saint-Michel: a Medieval Castle on a Small Island
Predjamski Castle: Integrated in a Cave
The castle wasn't built in one go; first written records exist from 13th century, though the first part (left wing) was probably built in the first half of 12th century. Middle part was added in renaissance, and the right wing was build around 1570. Some things were added and changed later, but since 1990 renovation work is in progress, restoring it to the original 16th century look.
Neuschwanstein Castle: the Classic Fairytale's Castle
The construction of the castle was carried out according to a well thought-out plan. The castle was equipped with all kinds of conveniences which were very modern, if not to say revolutionary at that time. Running water on all floors. There were toilets equipped with automatic flushing on every floor. A warm air for the entire building. American tourists are already familiar with Neuschwanstein; the in , was modeled on it.