Like Pen-y-ghent, the summit plateau of Ingleborough is Carboniferous millstone grit, whilst the underlying steep slopes are the Yoredale series of interbedded shale, sandstone and limestone. Below that, the open, flat area is Great Scar limestone which has weathered into world-famous exposures of limestone pavement (primarily on the other, western side of the hill).
The path is from the summit to Horton in Ribblesdale via Sulber; for those completing the Yorkshire Three Peaks route in the traditional anticlockwise direction, it's the final stage.