BATU MALOI
Batu Maloi Cave is often quoted in tourist leaflets as being a cave as long as 3 km. It is situated in the Kampung Tanggai Forest Reserve in the Johol district, 35 km from Kuala Pilah in Negeri Sembilan.
It is actually a series of huge granite boulders in the river bed and there is enough space inbetween the boulders to form a "cave". It is an interesting place and the river is very scenic. Strings and painted marks show the way through the cave, but care should be taken in wet weather in case of flooding.

GOLD MINE NEAR GEMAS
There is an old gold mine near Gemas in Negeri Sembilan. It is a series of tunnels where gold was dug by the British in pre World War 2 days. Today the tunnels are home to hundreds of bats and the tunnels have water inside, but can still be visited.

The Klang Gates Ridge is a prominent landmark to the northeast of Kuala Lumpur. It is formed of quartz and is a composite structure, consisting of brecciated vein quartz seamed with secondary quartz veins. Quartz is a common mineral formed of silicon dioxide. The Klang Gates Ridge is often mistaken for limestone and is said to be the longest such ridge in Malaysia/the world, at about 14 km long, and a maximum width of almosty 200m. It has been in the news a lot in recent years, due to the developments, which encroach closer and closer to the ridge. And in 2010 it was feared that a proposed highway would pass through the ridge.
As far as I know, there are no caves in the ridge. Quartz caves are not common, however they are found in South America, which has the world's best developed quartzite karst. Roraima Sur System in Venezuela, is the world's longest cave in quartzite, at 10.82 km . Quartzite is the metamorphised form of quartz. Brazil has the world's deepest quartzite cave, Gruta do Centenario, with a depth of 454 metres, and length of 3.7 km. It is situated in a mountain range, which is more than 2000m high. Thousands of swifts migrate to the cave to breed.