Marble Cathedral

It is considered the most beautiful cave network in the world, but you'll have a long journey to reach it. This spectacular Marble Cathedral, an intricate system of water-filled caverns, is set in the General Carrera lake in Chile's Patagonia - the second largest freshwater lake in South America. But to reach this remote place, located in the far southern tip of the country, visitors must fly from the capital Santiago, 800 miles to the next nearest large city, Coyhaique, and then drive on challenging dirt roads 200 miles south to the lake.