Have you ever attended a rope center, such as one in Dolní Polžice (gallery)? It's been slightly nontrivial but we have finished it. Polžice is the village where the enlightened and famous Czech 17th century aristocrat, Kryštof Harant z Polžic a Bezdružic, was born. The literal ;-) English translation of his name is
Christopher the Bastard from After Spoons and Without Satellites
A rope center consumes more energy than a bungee-jump that we tried a couple of years ago.