On the northern, uninhabited side of Mayreau you'll find Saltwhistle Bay, a double crescent of beautiful beaches split by a narrow palm-tree-fringed isthmus that seems to come right out of central casting for tropical ideals. The turquoise water laps both sides of the sandy strip, in some places only a few feet away.
Yachts drop anchor in the bay and occasional day-trippers come ashore for a bit of lunch and a sandy frolic. A few rickety huts along the shore sell cold drinks and simple snacks as well as souvenirs to passing yachties. It's a very low-key scene.
It's a 20-minute walk from the ferry dock over the steep hill.