Now an underground river in Philipines, called Purto Princesa, is also a competitor for one of the seven wonders of the world. The 8.2 kilo meter navigable underground river is the biggest and longest so far found out. The nomination for the world wonder has increased the chance for tourist attraction of the area in the Philipines. It is stated that it is the 2nd nominated for the world wonders. Naturally.