Grid reference on route: ST 15569 87069
Caerphilly is the first of the great concentric castles - this is where Edward I got the idea for Caernarfon, Conwy and Beaumaris. Gilbert de Clare was Marcher Lord of Glamorgan. He started the castle in 1268 to keep the rebellious Welsh to the north under control. It has complicated moats and defensive walls with towers and gatehouses. Inside was a Great Hall and other accommodation for the lord and his household.
The castle is now looked after by Cadw. More on their web site at http://cadw.gov.wales/daysout/caerphilly-castle/?lang=en . Lots more detail and excellent photos at http://www.castlewales.com/caerphil.html .