On Friday August 8, 2008 my wife and I experienced the California Cavern's Middle Earth tour. It was quite an experience.
Depending on your tolerance/enjoyment of tight spaces and physical challenges you can have a great or miserable time. Both my wife and I had an interesting, challenging and adventurous time. My wife didn't find it pleasurable - it's no walk in the park.
We are both very fit 60 somethings. We work out hard 5 to 15 hours per week. A 10 mile hill country hike is no big deal for us. But this trip really had us winded. Afterwards, we know we used muscles that we don't normally use.
The Middle Earth tour is reported to be one of the most extreme caving adventures in the US. You won't find any argument from us!
After suiting up in the provided coveralls, with lighted helmet and gloves, you set off with a great guide to the cave. You really need to follow their pre-expedition checklist as you absolutely will need rugged high top boots (you will be slogging through sticky mud that has pulled the soles off some boots and will pull yours off if not laced properly), knee pads (you will be on your hands and knees a lot! the long soft kind like for softball or volleyball are the best), and the proper clothing.
Contrary to their website - elbow pads were not recommended by our guide as they generally won't stay on your elbows - you wind up wearing useless wrist pads!
If you don't wear glasses, I would suggest goggles to keep any mud out of your eyes - be sure that they're anti fog... I had some problems with my glasses fogging up.
The cave is pretty much 55 degrees F year round, but the outside temperature in the summer is often in the 90s, so getting to the cave without overheating and then proceeding through the 4+ hour expedition without getting too cold is something to pay attention to. You will be getting wet and muddy, so follow their clothing recommendations.
The tour itself proceeds for about 1 mile underground. A lot of this is bent over, on your hands and knees or sliding on your belly using your elbows to pull you forward. In a few areas you have to squirm your way through.
The tightest section is a 5 foot vertical hole leading to the (aptly named) womb room that you can only get through with your arms over your head (to compress your shoulders). The hardest section is the worm squirm, very narrow about 20 feet long (I could be wrong, didn't have a measuring tape), with a hard to navigate sharp turn.
The most challenging parts of the trip were generally in the first half, with easy access to the main easy public walking tour path, allowing for an easy bailout if you freak!
After halfway, you are in a part of the cavern not easily accessible so really need to be comfortable at this point to make it to the exit.
No food, drink or bathrooms are available for the 4+ hour tour, so be careful with your intake beforehand. At the end are rustic shower facilities so you can clean up. Bring water and a snack as the small gift shop will probably be closed when you get out if you take the afternoon tour.
The caverns are beautiful and worth the visit. If you really want a strenuous adventure, are not the least bit afraid of tight spaces and you don't mind getting muddy and wet - consider the Middle Earth tour. If you're not up to it or are not totally fit - consider the walking tour.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.