The Waterside Spa at Diamond Mills

The Waterside Spa sits inside Diamond Mills Hotel where the Esopus Creek meets the Hudson River, and it's open to the public, not just hotel guests. It's adults-only, age 18 and up, with 9 treatment rooms and 32 treatments covering massage, facials, body work, nail services and facial waxing.

A day pass runs $75 and covers the indoor and outdoor relaxation areas, outdoor pool deck, sauna, hot tub, dipping pool, cold plunge and fitness center, all with creek and river views. Access is also included automatically if you book a massage, facial or body treatment. Walk-ins are welcome, and couples treatments are available. The signature service is the Waterside Bespoke Facial at $195.

For an extra layer of lounging, poolside cabanas can be rented separately (weather permitting), and there's a nail salon open seven days a week, though manicure and pedicure bookings don't automatically include amenity access — that has to be added separately. Light snacks and drinks are sold on-site, with water, tea and coffee complimentary to spa guests, and lunch available some days through the hotel's restaurant.

Hours run 10am to 6pm daily. Given the adults-only policy and the day-pass structure tied to treatments, this works best as a planned visit rather than a drop-in, especially if you're coming as a group, which the spa asks you to arrange ahead of time.