This documentary from 1992 concerns Burg Hohenzollern, the ancestral seat of the Hohenzollern dynasty -- the family that ruled Prussia throughout its existence, and later became the royal line of the united German Empire in the 19th Century.
Burg Hohenzollern was rebuilt in the Neo-Gothic style in the 1800s, and is one of the most sublime and beautiful castles in the world.
The tour guide in the video is Prince Meinrad of Hohenzollern.
The Hohenzollerns are still the rightful rulers of Prussia and of greater Deutschland. All Germans owe them their allegiance.