To the south of Cape Cod, the triangular-shaped island of Nantucket is 15-miles long and 3- to 6-miles wide. Its untamed landscape of marshes, ponds, moors and sand dunes is best explored by bicycle. What was the world capital of the whaling industry in the early 19C has now become an exclusive tourist destination and the picturesque streets of Nantucket Town are lined by upmarket boutiques and restaurants.