Kayaking in the mangroves north of Ao Nang. Excellent: 4 hours on a circuit, taking in coastal caves then a very deep canyon cutting into the steep limestone landscape. There are tons of crags that you just want to climb. As you go on, the canyon gives way to a huge area of mangroves, really quiet and total wilderness - there's no other way of getting to this place and sometimes the channel was only just enough to allow a kayak to pass. Saw monkeys, weird crabs, pipefish and a big scary monitor lizard.