Witness the calming beauty and deafening power of 11,000 marbles going down a marble run at the same time. Jelle Bakker, the self-described Marble Master, built this huge course over two months. The massive marble run takes up 132 square feet, though it stands only six feet high. You'll swear it's even bigger, though, when you see it all in action. Try keeping an eye on a particular marble to follow its path. Or simply take in the tide of thousands of marbles falling together. Either way, the marble tsunami will wash over you.