Map view:
http://apps.esriuk.com/app/GreatGeosites/3/wmt/view/5e0d44970b3a4b4dafb7da0404b2d8ed/index.html

No. 49 - Gaping Gill
http://www.geolsoc.org.uk/Education-and-Careers/100-Great-Geosites/5-Adventurous/Gaping-Gill

No 50 - Porth yr Ogof Caves
http://www.geolsoc.org.uk/Education-and-Careers/100-Great-Geosites/5-Adventurous/Porth-yr-Ogof

Also
No 11 - The Burren
No 16 - Malham Cove

My other half was looking through them all last night, there's some great images and really interesting stuff on there.

Interesting - thanks for drawing attention to this Alanw.

It's a shame that the image of "Malham Cove" isn't actually Malham Cove - just some random limestone pavement. Also the underground features seem to have been missed out, as is so often the case. Mind you, perhaps that's no bad thing in some ways . . . .

Porth yr Ogof is not in the correct location on the map.

Also,

14 Loughareema, Co. Antrim - The 'vanishing lake', formed on the Ulster White Limestone
46 Marble Arch Caves, Co. Fermanagh