They say money can’t buy happiness, but it can buy plenty of luxuries, including sprawling mega-mansions spanning tens of thousands of square feet, perfect for extravagant furnishings.

For the ultra-wealthy, no expense is spared. Why not add a subterranean pool with a waterfall or a high-tech car elevator for your supercar collection?

From estates decked out in 24-carat gold to homes sparkling with diamonds, click or scroll on to explore the world’s most over-the-top residences...