Today many 5 year olds eagerly anticipate their first days at school and a time of opportunities. How different from many of the 5 year olds who lived in large areas of the country less than 200 years ago. Instead they were expected to go down the deep dark dangerous coal mines to open ventilation doors or pull heavy carts of coal along narrow low passages. Until the Mines Act in 1842 when underground employment of all females and boys younger than 10 was abolished, those children had miserable lives. Subsequently when productivity improved, ponies and horses were used and in the 1870s there were an estimated 200,000 pit ponies in Britain with smaller ponies working in the seams with low ceilings and the horses in the thicker seams. They sometimes worked up to 16 hours a day pulling 30 tonnes of coal and perhaps never seeing the light of day unless they were fortunate and the pit closed for an annual fortnight when the ponies could be brought to the surface with sacks over their eyes to protect them from the light.  The last pit pony in Scotland retired in 1994  eight years before the last underground Scottish pit was closed in 2002 and the very last pit pony retired in 1999. in Wales.
Until the late 20th century there were many coal mines around the area and this statue symbolises the pit ponies and children who worked deep underground in atrocious conditions.
An interesting link and thanks to RockArea for the history challenge