Caerphilly Castle has been somewhat restored and its moat re-flooded. Not all, but some of its wooden parts have been rebuilt. Wooden bridge and wooden hoarding (rooftop for archers) can be seen in this video.
Caerphilly is different from the other Welsh castles in that it wasn’t built by Edward I. Instead, it was built by a powerful rebellious lord, Gilbert de Clare, who swore fealty to Edward I but had often been in rebellion against his father. Caerphilly was built about a decade before Edward’s other castles.
Caernarfon, built by Edward I, was the keystone castle of the ring around Wales. It was meant as a royal seat, and Edward I’s son was born there. Princes of Wales now are invested with their titles at this castle. It’s one of the few that wasn’t deliberately destroyed in the English Civil War.
Conwy Castle was, like others, destroyed. Its metal was stripped out and sold. However, so much of it is left that it’s been a tourist attraction since soon after it was disabled. If you watch this video tour, note the window seats and other wall niches.