El Drago de Los Vinos
Definitely worth a visit if you're staying in Northern Tenerife. It is said to be the oldest tree in the world, and looks like an overgrown sprig of broccoli! I believe it is now a kind unique to the Canary Islands. It's free to go and see, although the roads leading to the village it's situated in are quite windy. The tree itself must be over 20 meters high, and it makes a spectacular photo.
From journal Timeshare Trip to Los Gigantes