Queenstown in the south island is known to be the adrenaline rush capital of New Zealand – from here, you can go skydiving, bungee jumping, swinging over a gorge, or whitewater rafting.
Personally, I found the entire place to be over-hyped, over-priced, and under-impressive, but you can do all sorts of crazy things here – if you have the cash. For example, I’m not crazy enough to do this, but there are a variety of ways you can swing across a canyon – jumping off, tipping over backwards while sitting on a chair, riding a tricycle over the edge, etc: