History Channel - Hunting Hitler: The Tunnel (2015)

The team investigates General Franco’s summer palace as a possible landing strip for Hitler’s plane and uncovers a giant Nazi Swastika hidden in a nearby cemetery. By following the flow of Nazi Gold, the team discovers the town of Vigo and a secret UBoat docking site that could have aided Hitler in an escape out of Spain.

Part 1: The Hunt Begins
Part 2: Secret Nazi Lair
Part 3: Escape from Berlin