Where: Berlin, Germany
Constructed: 1695-1699
Extended: 1702-1713 and 1740
Most important renovation: 20th Century
Accessible: yes, interior with guide
Important fact:
The castle was severely damaged at the end of WWII. The restoration work took over two decades. The castle was part of West Berlin
at the time.
https://www.spsg.de/en/palaces-gardens/object/charlottenburg-palace-old-palace/