Their perfectly scrubbed decks bristle with security guards, while hot tubs bubble and helipads wink at the sky.

FORBES: Super Yachts Invade The Thames

It has two swimming pools, two helipads, a dedicated disco hall, 30 cabins, a cinema, a mini-submarine, and even its own missile defence system.

FORBES: Super Yachts Invade The Thames

Two helipads let guests fly in from Guatemala City to spend all their weekend time poolside, drinking in that vista and enjoying the services of a private chef.

FORBES: Lifestyle Feature

With 1.5m square metres of floor space, including two helipads, a giant shopping mall and a prayer area said to cater for 30, 000 worshippers, Abraj al-Bait is substantially bigger than America's two biggest buildings, the Pentagon and the Palazzo Hotel in Las Vegas, put together.

ECONOMIST: A Saudi tower