Middle Hill Colliery covered about a quater of a square mile centred around the 200 year old smallholding of Greenfields on the Valley Road near Saundersfoot. The colliery started off in the late 1600s and early 1700s and mainly comprised of opening the hillside where the coal was at the surface and digging long trenches down the valley to extract the coal. At the top of the ridge on the south side of the valley many bell pits were dug to get to the deeper coal. During the 1700s in the valley bottom where the coal was at its deepest a series of shafts were sunk in a line about 1000 metres apart due to early ventilation problems. Earlier shafts were also dug zig zag fashion down the valley and have been discovered at various times in the last 50 years. The one I discovered was 90 feet deep and dated from the pottery and oyster shells that came out of the top fill from about the early 1700s.
The spoil heap behind Greenfields was reduced in height by my father in 1978 when the house was rebuilt for our family home. My Uncle had layed the house sewage pipes into another shaft which is about 50 metres from the back of the house in the 1950s when my father was a young boy. The Colliery had finished by the 1860s when the new Tenby to Whitland Railway sliced through the middle of the workings. This created a division for the two parishes of East Williamston and St Issells and is now the edge of the Pembrokeshire Coast National Park. Vinyard Vale housing estate is now built on the top end of the colliery, a caravan site covers the middle section and a few houses and a small chalet complex were built at the lower end with the railway going through the middle. Before Bonvilles Court Colliery was built the original medieval road ran down to Saundersfoot down a valley which is now filled in by spoil from Bonvilles Court Colliery which diverted the original road up to and down the Ridgeway instead of down to the bottom of the Incline at Froghall and Westfield Road where the Saundersfoot Railway ran.