"A geothermal spa whose 102-degree milky-blue water is said to be excellent for the skin; visitors can book day visits or stay in on-site hotels such as the Silica Hotel or the five-star Retreat at Blue Lagoon, and the site is Iceland's most-visited attraction with scenic waters that pair well with northern-lights viewing." - Patricia Doherty Patricia Doherty Patricia Doherty is a writer who specializes in covering destinations, resorts, and cruises for Travel + Leisure and other publications. Travel + Leisure Editorial Guidelines