- About 500 yards to the south-east, down the Carnon Valley, is the portal of the Great County Adit that once drained all the mines in the locality.
- Although all the mines served by the Great County Adit have closed and it is unmaintained, it still drains many of their underground workings today; in the summer of 1980 the flow was 500, 000 gallons per day.
- Deep lode mining was only made possible by two innovations, the first of which occurred in 1748, when John Williams of Scorrier House initiated the construction of the Great County Adit, a phenomenal feat of engineering, which drained mine workings through a system of adits.
- Other examples are the Great County Adit in Cornwall, a 40-mile ( 65 km )-long network of adits that used to drain the whole Gwennap mining area, and the 3.9 mile ( 6.2 km ) Sutro Tunnel at the Comstock Lode in Virginia City, Nevada.
- It's difficult to find county adit in a sentence. 用county adit造句挺難的