I created a cave a long while back to use in unity so I created a unity package and put it up on Moddb. Somewhere along that process of exporting the model screwed up a bit. It's still usable, there's just a small chunk poking inwards on one side after exporting for some reason.
You may want to change the texture to something darker, it's your preference. The model looks much better in darker setting, the current texture is rather light which makes the joints stand out more. I'm not sure why the spoiler tags aren't working.
Download from attached ZIP or below
https://www.mediafire.com/?9aybu5l0amc9n6t
Originally made by me in Google Sketchup, I'm currently working on much higher quality a cave in Blender.
Specs: Windows 8.1 64bit | Nvidia GTX 650 | i5 Quad Core 4th Generation | 4GB DDR3 RAM