The main islands of Western Samoa are actually a couple of ancient volcanic cones rising up from the ocean bed. They are amongst the largest of the S Pacific islands with a dramatic and mountainous terrain that ample rainfall keeps lush and green. The two islands called Upolu and Savai'i, are well situated to receive numerous swells from both the N and the S. Upolu is the more developed of the two islands with the majority of the resorts and decent surf spots. The western island, Savai'i is much wilder with fewer known breaks, but potential for discovery. Generally, the waves are very hollow and powerful, breaking over shallow barrier or lava reefs usually within 500m of the shore. In a few spots big gaps in the barrier reefs allow the surf to break on lava reefs fringing the shore. The southern facing coasts hold the best quality waves, which are uniformly shallow and more suited to expert surfers. The N coast has fewer spots and receives less swell, making it more suitable for intermediate level surfers.