Sabang (1 of 2)
The Underground River (or St Paul's Subterranean National Park). The longest underground river in the world, it meanders for more than 8km beneath the surface, passing a bewildering array of stalactites, stalagmites, caverns, chambers and pools, the formations made eerier on your ride through by the shadows cast by the boatman's paraffin lamp. A journey into the darkness of this riverine cave is a truly unique experience. The limestone cave that the river passes through is thought to be the longest navigable river-traversed tunnel in the world (though a similar underground river recently discovered in southern Laos is perhaps longer).
