Wow...interesting find. I had a look at that planet too and found one cliff island 5.5km high! This one literally is an island unto itself, but in the ocean. You have to disable water to see its true depth! Can clearly see the textures are being stretched through the z-plane. My location is here:
Place "5.5km high cliffs"
Body "RS 1186-253-5-14155-899 3"
Pos (-1.140327605901451e-010, -1.048503379354659e-010, 5.867214257704789e-011)
Rot (0.4087074497547756, 0.1536206102477367, 0.128335624912406, 0.8904430897033246)
Date "2012.04.27 15:46:47.07"