A Look Inside St Barth Most Spectacular Spas. Newly expanded in 2018, the Spa Le Sereno features three full treatment rooms including the water pavilion, the island’s only beachfront treatment room. One Spa, three unique brands ( Ligne St Barth, Esthederm, Hydrafacial ) at Eden Spa a sophisticated union that delivers true island well-being and beauty. Not to forget Spa Sisley where the art of wellbeing meets the ocean..