Lists of mountains and hills in the British Isles in England, 366 in Wales and 11 in the Channel Islands. A Simm is a mountain the British Isles that is over high and has a prominence of at least . The word comes from Six-hundred Metre Mountain. There are currently 2,754 recorded Simms in the British Isles, including 2,188 Scottish Simms, 192 English Simms, 149 Welsh Simms, 1 Isle of Man Simm, and 224 Irish Simms. By definition, all Simms are also TuMPs (see below) and most, if not all, are mountains, depending on whether 600 metres or 2,000 feet (610 m) (e.g. a ), is used as the
Terminology of the British Isles of Celts inhabiting the islands, but this term was not used by the Greeks or Romans for the inhabitants of Britain or Ireland, nor is there any record of the inhabitants of the British Isles referring to themselves as such. Nevertheless, Roman administration later incorporated the province of Britannia into the praetorian prefecture of Gaul, in common with Hispania, which had Celtiberians. Armorica, where the Bretons would settle, was part of "Gallia Celtica", so there were tertiary relations between the Britons and Gallic Celts at least. In addition, the Parisii of Gallia Celtica are thought to have founded Aldborough in