PORTLAND. Nigel Graham found the questions about Portland caves, but being unable to register access to the Forum, asked if he could reply via me.
1) Sandy Hole ( Ammonite Passage). As Ed Waters said, ask Mike Read (Chelsea Speleo. Soc.). Mike & his mates have not published their survey, perhaps because they've not really abandoned the place!
I doubt very much it has anything to do with Culverwell (spring) as suggested, because Sandy Hole is far too deep, near the base of the Cherty Series of the Portland Limestones, & so far at least, dry. The spring is up on the Purbeck Formation. However, there are deeper-lying karst passage remnants at The Bill...
2) Fossil Cave: Open but it's acquired a substantial steel gate - why, when, by whom all unknown. In December 2010, Kev & Charlotte Hilton & I (all WCC) found the gate, a surprise to us, wide open, with no obvious way to lock it. The approach is as unpleasant as ever but the cave was remarkably clean, though we removed candle-stubs & some litter.
3) Blacknor Hole. Still no access but I've contacted a climbing organisation to see what's what on the cliff. After all the problems in 2003, first between householders & cavers/ climbers then between the two householders, followed by change of ownership and a new home built on the site, I thought it better to keep a discreet distance until things had settled.
4) Allotment Dig. I was one of its diggers. Blocked? Where? How? News to me, though I've not visited it for a few years. I'll take a look! Seems odd anyone would have blocked it deliberately, but the thought of a collapse is worrying as it's close to the surface.
5) Cheyne Weares. One or two ferrets have tried the rift in an old quarry just S of Cheyne House, without success (too tight even for ferrets).
6) Elsewhere on Portland.
The Inmosthay caves have all gone, though a fine sediment-choked phreatic tube revealed by the same active quarrying has been recorded.
No known active local caving on Portland at present, unless any youth groups still visit Flagpole Rift.
If you need any other information Nigel is happy to reply via his e mail, pm me and i will forward it to you
Pete