Secret of Supervillain Island

On a strange island off the coast of Croatia, the mysterious ruins of a long-abandoned hideout look like they once belonged to a James Bond supervillain.
Stories:
1) Vis Island Base, Adriatic Sea, Croatia;
2) Sutro Baths, San Francisco, California, USA;
3) Port Arthur Penal Colony, Tasmania, Australia;
4) Deutsche Stadion full scale model, Oberklausen, Germany

Next episode

S04E03 - Escobar's Castle