History Supreme Yacht — $4.8 billion

The History Supreme Yacht is the most valuable private object ever built, reportedly worth $4.8 billion. Designed by Stuart Hughes for tycoon Robert Kuok, this 100-foot superyacht is clad in 100,000 kg of solid gold and platinum, with a T-Rex bone statue and meteorite on deck. Its cost far exceeds #6, the Antilia residence, by $2.8 billion. Construction took three years, and the hull features armor-grade materials. The yacht's price per square foot of over $480,000 makes it 24 times more expensive than the average luxury home.