Link to CaveMaps surveys
Midway between BULL POT FARM and AYGILL are twin shakeholes, one contains a mass of scrap iron, the other is CASTERTON POT. The original entrance has now collapsed and entry now is down a hole under a corrugated sheet on the BULL POT FARM side of the shakehole. The 8m entrance pitch drops you directly into the first chamber. The way on continues via the second chamber to the 9m deep GUILLOTINE POT, where a small stream sinks. Above the pitch a passage has been pushed southwards for 15m past a calcite blockage to some low passage.
A rift at bottom of pitch leads to an aven and wet crawl with very tight bends, which becomes too tight This is supposed to be only a few metres short of the PRECAMBRIAN SERIES in AYGILL CAVERNS but the Pre Cambrian Series survey is in doubt.