Harmony of the Seas, an Oasis-class cruise ship, was delivered last Sunday and is ready to set sail. With a gross tonnage of 227,700 GT, she is the largest cruise ship ever built, surpassing her older sisters Oasis of the Seas and Allure of the Seas by some 2,000 gross tons, as well as 2.15 metres (7.1 ft) in length. It was constructed at the Chantiers de l'Atlantique shipyard in Saint-Nazaire, France where thousands of people gathered to see her off and now she's on her way to Southampton, England.

New York – 21,500,000

Atlanta, Georgia is now home to the world’s largest aquarium, the Georgia Aquarium, holding upwards of 8.5 million gallons of water and 120,000 animals covering more than 500 species from 60 different habitats.

This is the world’s largest mammoth cave and the bottom is out of sight. There are jungles inside it. The roof of the cave fell in and let sunlight in and all kinds of vegetation soon followed. It is one of twenty caves that have been found in Vietnam.

This is the largest and most expensive water fountain in the world. It is built and set in Burj Dubai Lake. It is over 900 feet long and can spray jets up to 500 feet high. The fountain can spray as much as 22,000 gallons of water in the air. Over 6,000 super lights and 25 color projectors help to create amazing dancing water sculptures. Watch the video to see the real beauty of this water fountain.

This jail situated in Maricopa County (Arizona, the USA) is one of the world’s largest jail systems. It has an interesting history and some strange traditions. For example, inmates have to wear socks and underwear of pink color.

The jail’s facilities got overcrowded in 1993. But in order to build a new facility, it was necessary to pay about $70 million, a huge sum of money. Maricopa County Sheriff Arpaio got an idea of constructing a Tent Jail using tents donated by the USA armed forces and inmate labor. This project cost was only $100,000. And it could house about 2400 prisoners who "volunteered" to participate in the Working Inmate Program. Those inmates, who don’t want to work according to the Sheriff’s rules, have to move inside the main facility and stay there together with the rest of the prisoners.