From Scotland’s Loch Ness to New York and Vermont’s Lake Champlain, monsters lurk within our planet’s fresh water lakes. These aquatic beasts run the gamut in appearance, and have been described by witnesses as everything from giant eels to modern plesiosaurs. Regardless of appearance, though, the one trait these sightings all share is the perceived enormity of the creatures involved. Naturally, any lake that could house one or more of these monstrosities would need to be of considerable size and depth, with Lock Ness itself spread out over 21.8 square miles and reaching a maximum depth of 744.6 feet. Lake Champlain is similarly large, if a bit differently proportioned, sprawling over 490 square miles, and reaching 400 feet at its deepest point. Lake monsters have a rich history in folklore, and are almost certainly related to such legends as that of Scotland’s water kelpies, or the Iroquois and Abenaki “Tatoskok.” It is undetermined whether the legends arose out of lake monster sightings, or the sightings are a result of the cultural memory of the legends; although, as is often the case, it’s probably a bit of both. So the next time you’re cooling off down at the lake over hundreds of feet of murky darkness, just try not to imagine what might be swimming underneath you.