In reply to UKC News:
Was in El Chorro Last week. Whilst there are signs up saying that you will be fined (6,000 euros!) for walking through the tunnel, according to the guys at finca el campanga (sp?) as long as you keep an eye out for the police, it is easy to get in & out. We went in there without any problems, however when the area is a bit busier there may be more police around.
There is also a route into the back of the gorge from a tunnel near the Mirabel, although again el camino del rey has been destroyed, there are some good bolts in place to allow you to climb up and around the destroyed area. Unfortunately they appear to have done a really good job blowing up the walkway at the village end of the gorge.
Although we didn't, we did see a few people camping inside the gorge which looked like a great spot (private beach, swimming in the gorge) and at least if you do this you don't need to go in and out so often.
In terms of why these restrictions are in place, we were told that a big school party were caught in the tunnels, and a couple of kids killed.