MS Liberty of the Seas is a Royal Caribbean cruise ship of the Freeom class which entered regular service in May 2007. The 15-deck ship accommodates 4,370 passengers served by 1,360 crew. She was built in 18 months at the Aker Finnyards drydock in Turku, Finland, where her sister ship Freedom of the Seas was also built. At over 154,000 gross tons, she joins her sister ship Freedom of the Seas as the largest cruise ships and passenger vessels ever built. She is 1,112 feet (339m) long, and cruises at 21.6 knots (40 km/h).