Spas with relaxation lounge

Napa Valley, California

Spa Terra is the cave-set spa at Meritage Resort in Napa Valley, open to hotel guests with pools, a relaxation lounge and on-site dining nearby.

Austin, Texas

A lakeside resort spa on Lake Travis in Lakeway, Texas, with pools, outdoor baths and treatments, open only to hotel guests.

Big Sur, California

Adults-only hotel spa at Ventana Big Sur with ocean-view treatment rooms, outdoor cabanas for couples, and a 24-hour fitness and yoga space.

Philadelphia, Pennsylvania

A private-reservation spa in Philadelphia's Manayunk neighborhood for date nights, birthday and bachelorette parties, with hot tub, sauna and massage chairs