The first-boringest day of the year would have to be the day after Christmas, when Christmas falls on a Monday and you are at work on a Tuesday.

Kitzezh, the Russian Atlantis, is a city that sank into a glacial lake to escape the onslaught of the Khanate, and it's said that you can a) see and hear it at the bottom of this large lake if you are a pious person, and b) that it will rise again eventually, like Cthulhu, but with onion domes.