Lake Baikal, Siberia, Russia

The first European to reach the lake is said to be Kurbat Ivanov in 1643.
In the past, the Baikal was respectfully referred to by many Russians as the "Baikal Sea" (Russian: Море Байкал, More Baikal), rather than merely "Lake Baikal" (Russian: Озеро Байкал, Ozero Baikal). This usage is attested already on the late-17th century maps by Semyon Remezov. To these days, the strait between the western shore of the Lake and the Olkhon Island is called Maloye More (Малое Море), i.e. "the Little Sea".
According to 19th century traveler T. W. Atkinson, locals in the Lake Baikal Region had the tradition that Christ visited the area:
The people have a tradition in connection with this region which they implicitly believe. They say "that Christ visited this part of Asia and ascended this summit, whence he looked down on all the region around. After blessing the country to the northward, he turned towards the south, and looking across the Baikal, he waved his hand, exclaiming 'Beyond this there is nothing.'" Thus they account for the sterility of Daouria, where it is said "no corn will grow."