Two zippers zipping concurrently at Boomerang Park. The boy on right is easily seen - but can you see the girl on the left? The zip lines are 3 meters apart and come off of a wooden deck built in to the limestone cliff (you can see the steep wooden steps leading of it at the top-right of the photo). Zippers wind up in a tree lined meadow below. Cables are half inch multi-strand steel.

Taken from the take-off platform. Two boys do their first zips on the 160 meter parallel zip lines - at Boomerang Adventure Park, northern Thailand. Yes, there's a fee, but it's less than $2 each.