Avacha Bay

Russia / Kamcatka / Petropavlovsk-Kamchatskiy /
 water, cove, invisible, губа (ru)
Avacha Bay (Russian: Авачинская губа, Авачинская бухта) is a Pacific Ocean bay by the southeastern coast of Kamchatka Peninsula, Russia. It is 24 km long and 3 km wide (at the mouth), with a maximum depth of 26 m.

Second largest bay on the planet. All the world fleet can fit in it. Freezes in winter.
Wikipedia article: http://en.wikipedia.org/wiki/Avacha_Bay
Nearby cities:
Coordinates:   52°58'35"N   158°33'40"E