El Barranco del Infierno (Ravine of Hell) is a long route for experienced hikers, there are thousands of steps up and down the precipice.
You can start by the fountain in Fleix and eventually come back by Benimaurell, it will take you over 4/5 hours.
For the less experienced walkers I would recommend perhaps just to the bottom and up again.

This is my experience:
One beautiful spring day, after a torrential rainstorm, my son, of five, and I walked down the steps. We could hear the gushing sound of water, we came to a fast running stream which we crossed, then we passed through an impressive hole carved in the mountain. We carried on down, passing and greeting other fellow walkers. Then we saw the impressive sight of a huge waterfall.

A waterfall in April

 

top

We enjoyed its freshness and steady rumble. We crossed the stream and my son insisted we go to the bottom, where the river flows. Due to the rain, it was flowing, but usually it is dry.
I now had to encourage my son to go back up the 2000 steps we had just descended!
I was surprised and proud of his achievement, a boy who suffers physical disability (sacral agenesis) and he was enchanted by the magic, the impressive beauty of nature gave him such energy.