Parts of Ashford Castle in Ireland’s County Mayo date from the 13th century, but much of the huge turreted structure was added in the 1850s when the estate was purchased by a member of the Guinness brewing family. A hotel since 1939, the property reopened in April following a comprehensive two-year restoration. It now boasts a spectacular new spa with an indoor resistance pool, a hammam, a relaxation suite and a scenic terrace with views across the serene waters of Lough Corrib. Guests can choose from product lines that include VOYA, based on seaweed from nearby County Sligo. Ashford Castle has always had a loyal American following — former guests include President Reagan, Sen. Ted Kennedy and John Wayne — and their number seems destined to increase.