I thought it might be useful to mention access off the M4. When approaching from the East, you pretty much have to use the big roundabout to do a U-Turn - come off at the 4th exit, but BE SURE TO STAY FAR LEFT ON THE 4th exit otherwise you will end up back on the M4 heading back East. This site is located in the grounds of the now National Trust run Tredegar house, so you have full use of the grounds AT ALL TIMES! Brilliant. There is a Fish and Chip shop 5 min's walk through the park, which (despite looking a bit dodgy - sorry to say) had AMAZING freshly cooked F&C. Well worth a visit. Found the site very convenient for the Cardiff East park and ride (£3 for the parking all day and bus tickets for all passengers included. For £5 you can use the bus ticket to go on to the bay and back on the Baycar bendy bus). Word of warning about the P&R - do not miss the last bus as it is in a secure compound that does not allow pedestrian access and LOCKS after the last bus leaves.  Site also very handy for a good variety of CADW sites - Caerleon and Caerwent, Big Pit coal mining museum in Blaenafon world heritage site, Caerphilly Castle and Castell Coch.  Not much further down the eastbound M4 is St Fagans welsh life museum - free and amazing.  Overall, plenty to do for a week or more. There is a large 24hr Asda 5 mins down the road for essentials.  Of course it is possible to hear the M4, at all times, but it's like a constant hum. You can either live with it or not. We were fine but it is a consideration.  Be prepared for very hard ground for the awning on the hard standings - large mallet and rock pegs essential. The last thing to note is that you put all of your trash in one bag as it all gets separated at the depot. Enjoy your stay if you go, I know we did very much.