Mansions have always been a pretty good indicator of a person’s wealth, but micro-mansions have recently become all the rage among the ultra-wealthy. They may be small in size but they're packed with state-of-the-art gadgets, and some even go deep underground. The one pictured is the Flex House in Zurich, Switzerland and was created by Evolution Design. It boasts panoramic views of the city, floor-to-ceiling glass panels, a spacious veranda and, of course, 'look at me' status.

Although they're sometimes billed as a more affordable way to experience luxury, the world's wealthiest can buy a fleet of micro-mansions in different locations – a lifestyle that's unavailable to most.