Dusseldorf, Germany - We were invited to an afternoon picnic in Dusseldorf.  We planned to arrive in the city early so we could sightsee before the picnic.  Unfortunately, we lost our way and only had time to see this beautiful castle called Benrath Castle.  This castle was built in 1756-73 and was the summer residence of Prince Carl Theodor von Pfalz-Sulzbach.  Here we are in front of the castle's lake.  We stopped to take a short rest...