Smugglers Cave Trail is a 3 mile moderately trafficked out and back trail located near Jacumba, CA that offers scenic views and is rated as difficult. The trail offers a number of activity options and is accessible from November until March.
off road driving
Moderate, not difficult. The hike marked on the trail map is actually a border patrol access trail/road. I ran into a border patrol officer and he gave me the coordinates to the cave (32.63490, -116.09223) you can go to the top of this trail and then go on the the cave but the trail on this map does not go straight there.
Fun day with great views.
This is not a rough or challenging hike, but it really is very satisfying. You might want to do some research before you go, because Smugglers Cave and the Elliott Mine are both full of all sorts of history. Unmentioned in the description is the Marshall Cabin, or at least its location, Moon Valley , which is just a little past the mine, the Other Smugglers Cave, and maybe the Overlook, at the far eastern end of Moon Valley. The scenery is spectacular, other-worldly. Camping here is also a hoot. The earliest article I've found on Smugglers Cave is on page 38 of the January, 1940 issue of Desert Magazine: http://dezertmagazine.com/mine/1940DM01/index.html (This site takes a certain amount of pride in being retro, in that you have to flip the pages of the magazine to the page you want. ) Then there is the hike a bunch of my friends took at In-The-Desert.com: