Meersburg and Mainau Island
Meersburg, seen in 1979.
Mainau Island, seen in 1979.  The island was developed by Grand Duke Friedrich I of Baden in 1853 as a tropical getaway.  Today, it is owned by the Swedish Royal Family.

Today (c2010) it is even more developed with more to see.  A nice diversion when you get weary of chasing castles!