Sidoarjo, Indonesia

This densely-packed Indonesian regency of 2.2 million people is no tropical paradise. With nearly 2,800 residents per square kilometer, Sidoarjo is a crowded urban sprawl on the outskirts of Surabaya. While its manufacturing and logistics industries drive economic growth, the bureaucratic headaches of this "Delta City" are persistent. And with the ever-present threat of the disastrous Lapindo mud flow, which has already displaced thousands, residents must contend with an unpredictable natural environment. For those seeking big-city amenities and job opportunities, Sidoarjo may be worth considering, but the high population density and environmental risks make it a poor choice for those seeking a laidback, rural lifestyle.