The bottom of the highway. See that small, flat-topped rock between the 2 sides? There's one more of them, but other than them, it's a huge open crevice that's about 15 feet long.
Information
Number 16 of 48 from the album
Spelunking in J4 with Kevin.
dated February 8th, 2003.
Captured with the Sony DSC-S85 (details).