[1] The exact location has not been clearly identified but the possible sites are in the modern ceremonial county of Somerset, England.
One of the possible sites is at Gatcombe which was occupied from the middle of the 1st century until at least the fifth century, demonstrated by the coins of Theodosius, Magnus Maximus and Arcadius which have been found.
[2] The second possible site identified is Charterhouse Roman Town.
[3] The settlement grew up around the north-western edge of prehistoric lead and silver mines, which were exploited by the Romans.
[6] Another suggestion is that Iscalis was at the mouth of the River Axe near Bawdrip.