Celtic toponymy from Brythonic *"crüg" 'hill' (Irish "cruach") From tribal name "Dumnonii" or "Dumnones", from Celtic *"dumno-" 'deep', 'world' From Celtic *"dubr-" 'water', *"dubrās" 'waters' (Welsh "dwfr"; Breton "dour") First element is possibly "dun", ' hill fort' (Welsh ddin, 'fort'). First element from Celtic *"duro-" 'fort'; in "Dūrobrīvae", Celtic *"brīwa" 'bridge' Possibly derived from Brythonic *"iska", 'water, fish' and *"leith", 'damp, wet'. From Celtic *"iska" 'water' (Irish "uisce"); second element in "Isca Dumnoniorum" (Exeter) is a tribal name (see "Devon") From Brythonic *"lēd-" [from Celtic *"leito-"] + *"rïd-" [from Celtic *"(φ)ritu-"] = "Grey Ford" From Celtic *"lindo-" 'pool' + Latin "colonia" 'colony'
Isca Augusta the remains of a Roman harbour had been discovered in Caerleon. Substantial archeologically excavated Roman remains of the Roman fortress can be seen at Caerleon. Cadw administers: The National Roman Legion Museum, located in the village, is part of the National Museums and Galleries of Wales. The museum exhibits artifacts and finds from excavations throughout the village including Roman currency, weapons, uniform etc. In March 2012 an episode of archaeological television programme "Time Team" that had been recorded in Caerleon aired on Channel 4, titled 'Rome's Wild West'. Isca Augusta Isca, variously specified as Isca Augusta or Isca Silurum, was