Iain Fletcher arrives safely at the bottom, aided by Ken Kirkman

Looking up the shaft - the yellow thing is the safety belt being taken up for the next person

In the Pinner Chalk Mines

Off on our journey into the Mines

Brian describes the geology

Bands of flint in the chalk

Is it a fossil?

Drip stone deposited where water percolates through the joints in the chalk

Hi Ho Hi Ho its off to work we go!

Signatures and initials left by miners using candle flames - these are the latest dates in the mines

Brian waits for his turn to ascend.

An intrepid explorer emerges into the daylight

Brian talks about the transportation of building stones

Looking at Pinner Church

An unusual tomb in Pinner churchyard

Looking at facing materials at the Woolwich

Macdonalds uses Travertine on its facings.  It is effectively a drip stone and it is formed sub-aerially, the holes are where the algae was growing