As of 2018, where is the deepest quarry in England?

Delabole is a village in North Cornwall. The village was formed from 4 hamlets in the early 20th century, these are Delabole itself, Pengelly, Meadrose, and Rockhead. Somewhat remarkably for such a small place it has four claims to fame:

It is home to the oldest working slate quarry in England;

At nearly 500 ft deep, the slate quarry is the deepest in England (and was for some time the deepest in the world);

It is the site of the first commercial wind farm in England;

and, finally, the village is the birth place of the Cornwall Air Ambulance.

The London and South Western Railway built a station alongside the quarry during the late 19th century. This generated freight traffic from the quarry and there was a reasonable amount of passenger traffic. Freight services were withdrawn in 1964, passenger services lingering on until the line closed to all traffic in 1966.