Tuataras are described as 'living dinosaurs' - an ancient sort of marine(?) lizard living in New Zealand
You are only likely to see a tuatara in their natural habitat on an offshore island. Most of these islands are protected.
One island that has easy access is Somes island in Wellington harbour. It's a quick ferry ride from Wellington city. Ask a ranger once you arrive on the island and hopefully they will tell you about where a few of them live. When I was last there I saw what is reputedly one of the oldest known tuatara.
Even if you don't see a wild tuatara, the island is a fantastic place to visit.
All the best.
www.rankers.co.nz about 5 years ago