(c) There must be an underground passage here!...

...that's what Abdullah said in famous Soviet action movie 'White Sun of the Desert', shooting at someone with a Mauser. Self-respecting fortress must have an underground passage. And here it is! On Strelkovy Island not far from the bakery. Its length is 1300 meters, it goes underwater under the island of Harakka in the Koivopuisto park and emerges from the slope of the Ullanlinnanmaki hill near the Compass cafe. Ambulances (if someone has appendicitis) or police (God forbid!) or firefighters (an unextinguished cigarette butt) can drive along it.