Sometimes, remarkable hideaways turn up in the unlikeliest of places. The island of Sumba lies 250 miles east of Bali in the remote Indonesian province of East Nusa Tenggara. Until recently, even lifelong globe-trotters had seldom heard of it. With an area of 4,270 square miles — almost the same as that of Jamaica — and a population estimated to be around 760,000, Sumba is no mere tropical microdot. But for centuries the island was isolated, undisturbed and practically unknown. A handful of Dutch colonizers came and went, leaving little permanent impression. Headhunting ceased only in the 1960s.