One of the best hikes you can make in the Anza-Borrego Desert if you like boulders.
The Spanish name for the area close by is Piedras Grandes (Big Rocks), this sums it up nicely.
At the parking turn south in a nice sandy wash.
Soon more and bigger boulders, but if you can find your way, it's surprisingly easy, for a huge boulder canyon that is.
Just as the canyon ends in a rather flat sandy area, a couple of huge boulders block the way, go around on the left.
Now head north/west following the terrain and eventually heading back along the Threstle trail.
Now entering Palm Canyon.
The stretch close to the palms is interestingly steep with huge boulders, take your time finding the easiest route.
This part is the most difficult part of the hike and sometimes dangerously steep if you make a wrong turn.
The GPS isn't accurate enough for an exact route, it will give you a general idea of one possible route.
Warning: This is an area with huge boulders, steep terrain, where making a wrong move may get you into serious problems.
How to get here:
Take the EC 119 (Number is on the road markers) Dos Cabezas (easiest), or the EC 109.
There are a couple of new roads, made for the windfarm, making it a bit more complicated.
A high clearance 4x4 car is recommended, but you probably can do without the 4x4.
While crossing the railroad, turn right and immediately turn left away from the railroad.
At the end turn right into the Mortero Palms parking.