I'd hesitate to call this definitely a Clearwater Cave exit but that's where it falls in my image sequence. It's certainly the exit of one of the mulu caves.
What's the difference between an entrance and an exit? Just the way you're traveling, I guess. I don't recall any one-way signs but the entrances to the shoe caves are signed on the surrounding trails so I guess that forms a semi-official one-way system.
Another way to get to the Gunung mulu National Park is from limbang. You take a boat up-river and then hike the Headhunter Trail – typically a three to four day hike assuming you are reasonably fit (and don't meet any headhunters).
The reason that sprang to mind was the skull-like shape just up and right of the center of this photo. It's actually just the way the sun in breaking through the jungle canopy to illuminate that one spot on this cave exit, but it does look like a disembodied head!
