Nuclear power has been around for decades, but it still isn't cheap... in fact, it may result in one of the most expensive objects on the planet. Cost estimates for the UK's proposed Hinkley Point C reactor have crept up to £24 billion (about $35 billion), making even some of humanity's more ambitious construction projects seem like small potatoes. The Large Hadron Collider cost "just" $5.8 billion to build, the BBC notes. About the only thing that rivals Hinkley on Earth is Chevron's recently completed $54 billion natural gas plant in Australia. If you're not picky, the International Space Station's collective modules top everything at a total of $110 billion.