The Northern Soviet waters were equipped with a string of lighthouses to mark the treacherous passages through the dark times of the years. To make these remote beacons autonomous, they were powered by small nuclear reactors. EnglishRussia has the fascinating story of how that all turned out, along with some pretty cool photos.
Then, after the collapse of the Soviet Union, the unattended automatic lighthouses did it job for some time, but after some time they collapsed too. Mostly as a result of the hunt for the metals like copper and other stuff which were performed by the looters. They didn’t care or maybe even didn’t know the meaning of the “Radioactive Danger” sign and ignored them, breaking in and destroying the equipment. It sounds creepy but they broke into the reactors too causing all the structures to become radioactively polluted.