While mystery clocks have been produced by Cartier for nearly a century, to use this perplexing optical illusion that will fascinate the most curious of minds with a tourbillon is not only an incredible feat of engineering, but one that was only made possible by Cartier. Launched in 2013, the Rotonde de Cartier Mysterious Double Tourbillon is an impressive timepiece that achieves the double effect by the tourbillion cage itself rotating once every 60 seconds, and a glass disc that is mounted on making its own revolution once every five minutes, creating a fascinating dance between the two. The impressive complication is housed in a lustrous platinum case, and is a delight to behold and ponder at.