Harmony of the Seas is an Oasis-class cruise ship built by STX France at the Chantiers de l’Atlantique shipyard in Saint-Nazaire, France, for Royal Caribbean International. With a gross tonnage of 226,963 GT, she is the second largest passenger ship in the world, larger than her older sisters Oasis of the Seas and Allure of the Seas, but surpassed by her newer sister Symphony of the Seas. In length, however, Harmony of the Seas is the longest cruise ship in the world.