A loch is the same as a lake. Which is a big area filled with water. There are many famous loch's but the one you have mostly likely heard of is Loch Ness which is famous because of the Loch Ness Monster myth.
Loch Ness
Take your pick between Loch Lomond (the song) and Loch Ness (the monster).
Probably Loch Ness, but there are others.
i did me the famous loch ness monster
Lol loch ness
You are probably thinking of the Loch Ness Monster, which is said to inhabit Loch Ness, a big lake in the middle of Scotland.
Bigfoot, The Loch ness monster, and aliens.
It added a cultural icon and made Loch Ness more known in the area.
Loch Ness
That would be Loch Ness - there is "reported" to be a monster there it has never been proved, despite many searches over the years.
Loch Ness