Caerphilly is located just a few miles north of [wiki=288a6430a6f57a76e823d74e0dd750d2]Cardiff[/wiki], on the A469 road.
Arriva Trains [http://www.arrivatrainswales.co.uk/] run services to Caerphilly from Penarth via Cardiff Queen Street and Cardiff Central stations.
Bus number 26 [[List of bus routes in Cardiff|starts from Cardiff Bus Station and goes to Caerphilly. In fact you can cover Castell Coch [url=http://en.wikipedia.org/wiki/Castell_Coch]]]on the way to Caerphilly, because the bus stops very close to Castell Coch (in the village of Tongwynlais [http://en.wikipedia.org/wiki/Tongwynlais[/url]), on it's way from Cardiff to Caerphilly. A 'Network Dayrider' ticket (£7.00/adult) will give you access to all Cardiff buses plus all buses in South East Wales, including Bus 26, for the day. A one way ticket just for Caerphilly will cost lesser but route A (Graig-y-Rhacca) and B(Sengenhydd) travel to Caerphilly Town Centre(The same place that route 26 goes) in a much faster time. A,B and 26 are all operated by Stagecoach.
AA and WTB 3* B&B. All rooms en-suite.
Both the Premier Inn [url=http://www.premierinn.com/]]and Travelodge [http://www.travelodge.co.uk/[/url] chains have hotels in Caerphilly, due to its proximity to the capital.