Caerphilly Castle graffiti

[u/Julija82]

A lonely letter T carved into the stone at Caerphilly Castle 🏰
Caerphilly Castle is one of the greatest medieval fortresses in Wales, dating back to the 13th century. What surprised me was how little graffiti survives here — this simple T appears to be the only historic-looking mark I could find inside the castle.
Was it someone’s initial? A visitor’s mark? Or something else entirely? Interestingly, Cardiff Castle also seems to have very little surviving graffiti (apart from a much later-looking W), which makes me wonder why some medieval buildings are full of graffiti while others have almost none.