RiverSpa, located near the Dobbs Ferry train station and Mercy College, is probably one of the best spas in the area. Overlooking the Hudson River, RiverSpa is set in an old warehouse that gives you some doubts as you're weaving your way through it. But when you get there, you can't help but be impressed. It's pricey, but worth it. The hair stylists and make up artists are incredible, and there is a good selection of spa treatments.