On the day we rented a car, we drove east to the shore, across the center of the island and then returned along the south and west coasts. Across the center is a long, windy (“windy” as in to wind around, not the blowing air kind of “windy”) trek through sparsely populated areas. Also, there are not a lot of gas stations, so we needed to keep a close watch on the gas gauge.
Devil’s Bridge National Park is on the east coast, taking the full fury of waves coming across the breadth of the Atlantic Ocean. So it gets pounded pretty hard, thus the hardcore rock formations.