Is it a Canon or a cannon? This 5200mm prime lens is the world largest known SLR lens. It's said that only three of this toys are around, all made in Japan, and all in private hands. The lens focuses on objects 18-32 miles (30 – 51.5 km) away. If it was even more powerful the earth's curvature would be a serious issue. The minimum distance is 400 feet (120 meters), the weight is around 220 lbs (100 kg). One of these monsters sold in eBay a few years ago for a ridiculous $50000. The video above shows still images of the lens, the zooming sequence at the end is a simulation.
Not the best lens for a travel photographer! :-)