The crossword solution for the term WELL-KNOWN LOCH is NESS, a four letter word. The Loch NESS is a large freshwater loch in the Scottish Highlands, located in the Great Glen. It is one of the most famous lakes in the world due to its association with the legendary Loch NESS Monster. The loch is over 23 miles long and has a maximum depth of 755 feet. It is also home to a variety of wildlife, including otters, ospreys, and salmon.