Everyone remembers Jeb Corliss flying through a cave in China. Well Italian-Norwegian Wingsuit / BASE-jump athlete Alexander Polli has gone one smaller, flying through a tiny natural arch in Spain.
He does a couple of test flights first then jumps from a helicopter to reach speeds of 250 km/h (155 mph) following an carefully worked out line to the mouth of the arch or "bat cave". You only get one attempt, any error and it is splat. A huge level of commitment.
The arch is located in Roca Foradada Mountains in Montserrat, Spain.