a county of Wales, bounded on the north by the Severn sea or St George's channel, Cardiganshire on the south, the shires of Brecknock and Glamorgan on the east, and Pembroke-shire on the west. Its greatest length is between 30 and 40 miles, and its breadth upwards of 20. The air is wholesome, and the soil less rocky and mountainous than most other parts of Wales, and consequently is proportionally more fertile both in corn and pasture. It has also plenty of wood, and is well supplied with coal and limestone. The most considerable rivers are the Towy, the Cothi, and the Tawe; of which, the first abounds with excellent salmon. The principal towns are Caerphilly the capital, Kidwelly, Llanidloes, &c. This county abounds with ancient forts, camps, and tumuli or barrows. Near to Caerphilly, towards the east, may be seen the ruins of Castell Carreg, which was situated on a steep and inaccessible rock; and also several vast caverns, supposed to have been copper mines of the Romans. Near this spot is a fountain which ebbs and flows twice in 24 hours like the sea.