Wednesday, June 13, 2012

Moili'ili Karst Exploration

June 11, 2011

Rather than go into a long dissertation about how this limestone cave system was created here under the shadow of the Ko'olau Volcano, the short version is that a very long time ago the sea level on O'ahu was much higher and the area near the University of Hawaii was once covered by a coral reef.  As the sea levels dropped the reef was exposed to the air and died.  Springs and runoff from the mountains above ate into the limestone layer left by the reef creating a network of caves.  Most have either collapsed or been filled in over the years.  These systems are also found other places on the leeward coast. This fantastic link that explains everything about this system in far more detail than I could.

Before we go further, despite what the link says the water in the cave system is anything but clean just from visual observation.  Further, access to the system is tenuous at best and there is a danger of both flash flooding and the possibility of a cave in.  Neither scenario is a good one because there is only one way in and one way out of the cave.  No directions and no names and, for the record, I was never there either.

After entering the cave system, which required crawling through the muck through a few low areas we entered the still low and shallow karst.  Fair warning, armed only with the Nikon AW100 which is waterproof, photography was a little challenging especially with everyone moving around in the dark with headlamps so a lot of the pictures are blurry.  Two of the members of the expedition were armed with DSLR's (you guys are mental!) so hopefully they were able to get better shots.

Entering the cave system
Initial impressions of the karst were that it was hotter than anyone expected and quite humid.  Camera lenses began to fog in the stuffy air and litter from the urban environment above in the form of used ketchup packets, straws, plastic bags, and other common trash which is washed in during rain storms could be seen regularly.  The group paused to take in its new surroundings before wading into the water to continue.

Checking equipment and adjusting to the cramped quarters.  Also wondering why we were even here!
Setting up a shot
After the short pause the first members of the group waded into the water and started working slowly further into the cave. The muck continued in the form of a heavily silted bottom which was usually about a foot deep but was occasionally knee deep.  The depth of the water initially was about waist deep but about midway through the exploration it reached up to over chest height and then up to neck height.  It easier to put feet out to guard against jagged boulders and tread water in one section than to try and walk.

Venturing deeper into the cave...
Everyone joked about various creatures that would be waiting to spring up from the depths but I had already planned for that by taking up the rear position in the group figuring I'd buy enough time as members of the group were eaten to escape.

Limestone formation
 There really wasn't a whole lot to see but some of the rock formations hanging from the ceiling or poking up from the water were pretty interesting.  The entire roof of the cave was fairly brittle and when touched it would crumble.
One of the pilings driven down into the Karst to support a building above.
Throughout the cave were the pilings that had been driven down to support the various buildings above us.  I can't help but wonder how long these will last as the re-bar inside them is clearly rusting through.  It will probably be decades but I'll remember not to purchase any real estate here!

Another picture
  The size of the group meant plenty of headlamps which illuminated the caves pretty well.  Being down here alone would probably be much more nerve racking.  Camera flashes punctuated the lighting periodically as we all documented our experience.

Exploring a shallow section
After a shallow section the water level deepened.  The point of the group swam ahead and reached the pile of fill that marked the end of our explorations.  We turned back towards the entrance and now that I was at the front of the group I was able to get a few shots of the cave without any headlamps or people in them.

A deeper section... up to my shoulders
Moili'ili Karst
I didn't see much in the way of plant or animal life, just a few roots hanging from the ceiling from trees above and some type of small fish.  In fact I'd call it more of a guppy than a fish.  Others reported seeing some type of shrimp.  Someone spotted a centipede- something no one was excited to hear about but it made for great conversation about how many more there might be down here, what mutant sizes they would reach, and how their appetite for human flesh would have developed.

Returning back to the entrance.
On the return leg we paused again briefly in a loose circle with everyone taking pictures before leaving the cave and climbing through the mud to the surface.

Group Photo
While it wasn't much of a hike or trail, I'm glad to have had the opportunity to visit this unique and interesting place.  Perhaps someday I'll return but I can assure you, it won't be alone and it won't be anytime soon!

If you've got about 9 minutes and 1 second to waste you can watch this series of video strung together as we swear, complain, joke, and trip our way through the waters of the karst.  This is taking Not So Great to a whole new level- pretty crappy!  Those with sensitive ears will have to pardon the language too.

Andrew Agcaoili put together a better video of our visit and was nice enough to give me permission to share it here.  Be sure to check out his other videos on YouTube

There will be other write-ups about this visit to the Moili'ili Karst and I'll update this post as they are published.  More pictures from this adventure and others can be viewed on Flickr.  Aloha and mahalo for reading!


  1. Fascinating journey and photos. I enjoyed them very much! (:

    Earlier, I had been researching Moili'ili Karst but had not been able to find the entrance. One person mentioned a sewer tunnel or something similar but I have no idea. If you ever do go back, I'd love to join you (if access is not too extreme or illegal). ^^;

  2. I've toyed with the idea of going back... not sure though. I'll let you know if I do. Aloha!

  3. Aloha and thank you! ^_^

  4. is there any chance youd be willing to share how/where to find the entrance?

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  7. As I type this I am in my car just 15 feet from the entrance. Me and a friend were going to go down there this morning. We found the area that the grate is at easily enough but finding the grate itself was not so easy. It is obvious that the last time anybody went down there was probably the trip when this blog was written. Homeless have been making their bed here at night for the last several years it seems. The grate was buried under a ton of trash and bedding material. Finally found the actual grate but someone will need a shovel and maybe a prybar to completely uncover it (not to mention some Lysol would be a good idea). Also afraid of finding a lock once it is uncovered.
    Maybe we will try again some other day.

    Here are a couple pictures:

    The two deleted posts were the same info contained in this post - just fixed some typos.

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  9. Realized I lost my sunshades that magnetically clip into my glasses so went back to look for them. I didn't find them so if you are ever there and find them let me know! I uncovered more of the grate and took a couple more pictures. Also let me know if someone plans a trip. Fairchilr001 at gmail.
    This one was taken through the grate: