Gua Kelam, which in local dialect means dark cave, is a 370-metre mining tunnel in Kaki Bukit, Perlis. It is part of the limestone cave system in northern Perlis. Gua Kelam was enlarged in 1935 by the British to transport tin ore.

It started with the discovery of tin by a Malay man by the name of Nayan at Sungai Pelarit, who later sold the operations to the Kong Fatt Mining Company. The tray system was used to mine for tin. With miners digging pits as deep as 200 meters. Downpours often caused floods that trap and drowned many miners.

It is one of the most distinctive caves and famed for its enchanting 'cave walk' where visitors enter from one end of the cave and exit at a different locations. The only path to the cave is via an eight-foot-wide wooden suspension bridge. This bridge links Kaki Bukit to the Wan Tangga Valley, a valley on the opposite end of Gua Kelam. Back in 1935, an Englishman saw the water pathway as a brilliant method to transport tin ore from a mine located near the stream entrance through the underground cavern to Kaki Bukit.

Today, locals and tourists make their way through the cave via a brightly lit wooden walkway inside the cave. You can still find remnants of the tin mine operation within the cave. As you make your way through the cave, the swirls of a dark subterranean stream, together with squeeling bats and dripping water from the stalactites, form a concerto of natural sounds.