This is La Catarata de La Fortuna, an amazing waterfall just outside of the small town Fortuna which is also home to the volcano Arunal. There are organised trips to the falls, but we thought we'd do it by foot. After getting lost, we made it onto the 5km uphill dirt track to the falls, which has got to be one of the hardest walks I've done. At the end is a terrifyingly steep drop to the base where at least you can have a cool dip. A tough excursion, but worth it - remember to take drinking water!