As in the Scottish lake Loch Ness, a cryptid serpent, called Lagarfljótsormurinn by locals, is believed by some to live in the depths of Lagarfljót.
The village of Fljótsdalshreppur is located close to the glacier of Vatnajökull and to the lake of Lagarfljót, near the valley of Fljótsdalur.