A lens that can look behind itself -- the very idea of it nearly boggles the mind, but it's what the Fisheye-Nikkor 6mm f2.8s claims to be able to do, delivering a viewing angle of 220-degrees. This gargantuan fisheye lens was introduced in 1972, and was reportedly only available through special order. The price of getting your hands on one today? Oh, only about Â£100,000 ($161,210 American) for a lens in mint condition, and only from Grays of Westminster, a London Camera shop that deals exclusively in Nikon products. It isn't the first time this prodigious piece of glass has shown up, two years ago an identical lens hit eBay to the tune of $34,020 -- a veritable bargain, by comparison. Check out the source link below to peek at the sale. Wallet can't take the damage? Scope out "more coverage" for a bit of Nikon history.