Meghalaya is a north eastern state of the Indian federation, one of the smaller ones also. Because of the complex borders of India in this corner, it is bordered by Bangladesh with its lowlands to the south. To the north lies Assam, famous for its black tea, along the northern border runs the river Brahmaputra.
Meghalaya is located in the southern forelands of the Himalayas, most of the country lies at an elevation of around 1,000 m asl. This mountain ridge is a very effective barrier for water laden clouds from the Indian Ocean, as they are forced to rise, cool down and then rain. So this part of India has a rather cool and wet climate, the comparably low temperature for a sub tropic country, is very nice for European tourists. But on the other side, frequent and heavy rains are typical for the country. Some say, it is the wettest place on Earth, which sounds a bit exaggerated, but it definitely is one of the wettest places. The inhabitants know this, so they called their country Meghalaya, which means the abode of the clouds.
The mountain ridge of Meghalaya is mostly composed of limestone, at least at a certain elevation. This layer is heavily karstified, obviously a result of the heavy rains and the ideal temperature. The caves have temperatures a little above 10 °C, an ideal temperature for limestone solution. The abundant vegetation produces the necessary acids for solution and the amount of water results in high degrees of erosion. And despite the ideal situation, which resulted in numerous, big and beautiful cave systems, most of the caves were discovered very recently.
The explanation is, as often, a political one. India is rather poor and the locals do not have much spare time to explore caves. But, as often in Third World countries, there is an enormous gap between the poor and the few rich people. There are many families, which are rather rich, and the younger generation is able to do the same sports as most of the people in western countries. A result of this is the Meghalaya Adventurers Association, which was formed in 1990. A group of young people, interested in sports, climbing, exploring, who tried to explore the local caves. For more than ten years British, German, American and other western cavers went to Meghalaya and made combined trips, on one side exploration of absolute virgin caves, on the other hand training for the locals in all necessary caving techniques.
This exchange was obviously extremly productive: in a few three week expeditions, dozens fo huge caves were discovered, explored and surveyed. The Meghalaya Adventurers Association organized the trips very well, which would have otherwise been extremely difficult for foreigners. And British and German cavers - at home in countries were holes are called caves if they are longer than five meters - explored 25 kilometers of virgin passages every year!
This development is extremely new. The caves are normally very big and many parts are very easy to visit. But none of those caves is developed for tourists in any way. There are no paths, no light, not even acceptable roads to the caves. Still there are dozens of webpages which promote caving trips in Meghalaya. If you have a closer look, you will see that all of them are more or less identical. They are based on a sort of brochure by the Meghalaya Adventurers Association, intended to persuade foreign cavers to visit Meghalaya and help exploring caves. Unfortunately the text saounds as it was very easy to visit all those caves and that the trip was suitable for the average tourist. Please be aware, that all those caves are real wild caves. And the trip offered takes two weeks and is rather strenuous. The whole trip is organized very well and the Meghalaya Adventurers Association is very competent in guiding people through their caves. But still you should be aware, that it will be a sort of expedition, not the visit of a few show caves.
As far as we know, there is still no developed cave in Meghalaya, which could be called show caves. There are also no other underground tourist attractions we know of. Many links below will lead you to various versions of the text mentioned above. The other links will bring you to the reports of some recent expeditions.