The spa and skin-care brand Espa recently opened a spa at the Vdara Hotel and Spa in Las Vegas—its first outpost in the western United States. While the British company has more than 350 spas in 55 countries, this is only its third U.S. spa, after the Acqualina Spa by Espa, in Miami, and Espa at the Joule, in Dallas. The new facility occupies two levels at the hotel and spans some 18,000 square feet. Its interiors feature sapele wood and river-stone flooring, mink-marble accents, and a gleaming two-story water…