Upper Palaeolithic deposits, including bones of Homo sapiens, have been found in local caves, and artefacts dating from the Bronze Age to the Middle Iron Age have been found at Mount Batten showing that it was one of the main trading ports of the country at that time. An unidentified settlement named 'TAMARI OSTIA' (mouth/estuaries of the Tamar) is listed in Ptolemy's Geographia and is presumed to be located in the area of the modern city.

What is the name of the location cited by Ptolemy that is believed to have been located near modern Plymouth?