The last great North American glacier retreated north 10,000 years ago, and in its wake, there was Martha's Vineyard. The western portion of the Island is marked by boulders, sand and clay deposits from the glacier. But nothing is more dramatic than the colorful cliffs of clay at Aquinnah (Gay Head). The cliffs are open for public viewing, from a high point near the Gay Head Lighthouse. From this vantage point, there is water on three sides, and Noman's Land can be seen to the south and the Elizabeth Islands (both part of Dukes County, but mostly unoccupied) are on the opposite horizon. The view from here of the cliffs and the lighthouse is breathtaking. Equally impressive, though, is to follow a boardwalk down to the ocean, where there is a public swimming beach and a view of the clif... 04/24/2007