High Island Salt Dome, Texas

High Island is a salt dome directly on the coast, bulging 32 feet above sea level, making it the highest point on the Gulf Coast between Mobile, Alabama and the Yucatan. It is ringed by around 200 oil wells, some of which are still pumping. High Island was also an early minor sulphur mine site. On the mound itself is a community of a few hundred people, and an old mineral springs resort.