Brouton Bay on Shimushir Island...

contains a once secretive James Bond-like submarine base used during the Cold War. The Soviets artificially expanded the natural opening of the caldera to the sea (seen in the distance behind the ship) in order to enable nuclear missile submarines to pass into the protected and hidden harbor:

We explored the long abandoned site - since ~ 1994 - and entered some of the decaying buildings filled with, you guessed it, more relics from the past:

Before we left I couldn't resist having my picture taken with Lenin: