The Spa at Four Seasons Hotel Washington, DC

This is the spa inside the Four Seasons Hotel in Northwest Washington, D.C., on Pennsylvania Avenue near Georgetown. It's an adults-only, luxury-tier hotel spa, open daily from 9am to 9pm, with access through day passes as well as for hotel guests.

The standout feature is a private Contrast Therapy Room pairing a cold plunge with an infrared sauna, aimed at the usual contrast-therapy goals of better circulation and reduced inflammation. Beyond that, the spa covers the standard luxury-hotel menu: massages, facials, body scrubs and wraps, plus a few less common add-ons like IV therapy and a vibroacoustic Mind Sync treatment that uses sound and vibration on specialized tables.

For something more involved, there's a Night Spa package: an 80-minute massage followed by light food and champagne with private pool access, bookable for a couple or as a foursome. Couples treatments are offered more broadly as well, not just through this package.

The spa also has a restaurant or café, a relaxation lounge, a fitness center, and the pool and sauna already mentioned. Four Seasons also runs a Fitness Club and Spa Membership program for those who want ongoing access rather than one-off visits. Given the Luxury price tier, expect rates in line with a top-end Washington hotel spa, though exact treatment and day-pass pricing isn't listed here, so it's worth confirming directly.