(CNN) -- Borneo is brimming with valuable natural resources such as petroleum, diamonds, teak and rubber. Yet one of its biggest attractions is what it doesn't have -- namely, extensive human development.
The island in the Malay archipelago is the third largest in the world (behind Greenland and New Guinea). But it only has about 2,500 miles in highways, leaving much of the land untouched by civilization.
As the idea of "ecotourism" catches on, jungles are giving four-star hotels and luxe spas worldwide a run for their money. Many adventure travelers rate Borneo as one of the premier destinations in the world.
TravelGuide strapped on hiking boots and tromped around the Malaysian state of Sabah in northern Borneo to check it out. Here are some of the sights and sounds....