Underground tunnels in Orange County, Ca

Sorry, no underground alien bases, or anything, but...

When I was a kid I used to spend a lot of time exploring the storm drain system here in Orange County, California. Some are rounded tunnels small enough that you have to crouch to walk through them, while others are twenty foot high squarish underground tunnels, big enough to drive a large truck through. There are miles and MILES of these tunnels throughout much of Orange County.

It's been probably ten years since I've been in any of them, but I still remember where a couple of the entry points are. For instance, there's a tunnel set that leads from approximately Mormon Church off of Trabuco road all the way into Irvine. That particular tunnel is fairly simple. Mostly a straightaway. Simplest way to find it is to go to the intersection of (EDIT: Bake and Toledo: Here's a map) in Lake Forest. Go down into the forested area. It's right near the end of the horse trail from the Serrano stables. You'll find a large 'triplicate' tunnel (all three run parallel). Go through maybe a quarter of a mile, and it will take you to the main straightaway. If you go in one direction you'll find a large, truck-sized straightaway that alternates between open-to-the-air and underground. Or, if instead you make a right, there's a smaller rounded tunnel that leads in the opposite direction towards the church. That's where the branch is. Local gossip had it that the branch led to some sort of room, but I was never able to navigate it adequetly to reach the end of it.

I remember there being another entrance to a more complicated system somewhere behind the Western Digital building in Irvine. It's been a while, but I vaguely remember it running near a set of railroad tracks. Unfortuanately WD security tended to make getting to it difficult, but that one was a lot more complicated, with some areas that were architecturally more difficult to describe. Not just tunnels, but not exactly 'rooms' either. One branch I remember leading directly to a warning sign saying not to proceed because it led to the El Toro Marine Base. At the time, the base was still occupied, and I was never brave enugh to follow it.

There were lots of these sorts of tunnels. Again, crisscrossing through a lot of Orange County. Miles and miles of them. The most interesting ones were generally in Irvine. When it was still being newly developed there were several major tunnel entries that were completely open to the air. Simply walk into a construction area and you could find them. Now that's Irvine is developed it might be more difficult to find them than it used to be...but it might make for an interesting project to anyone so inclined.

Anyone else gone spelunking here in OC?

Bucket Man


[edit on 2-11-2006 by LordBucket]

They are potentially dangerous.

Not only sudden flash floods, but the old debris and trash in them will decompose and leave pockets of methane or other gases.

The maintenance workers in those tunnels always work in pairs and have gas and motion detectors on their persons at all times.

Best to stay out of those.