This is a 15th century representation of Ptolemy's map depicting the 'known world' back then based on his work 'Geography'. I would like to know where the area I enclosed in red is bounded by as per modern geography, and whether the details provided in this depiction was accurately based on Ptolemy's description.
More or less, it's something like this:
Not all the details are correct, but that is to be expected for an area that is known mostly by hearsay.
- The Malay Peninsula and Sumatra are conflated;
- Indochina and Borneo, and possibly the Philippines as well, seem to be conflated;
- The Gulf of Thailand is clearly seen, but is conflated with the South China Sea;
- Java seems to have been conflated with either Australia or Antarctica - the great southern continent at any rate; and
- The east-west extent is exaggerated - the longitude problem manifesting itself, possibly enhanced by uncertainty about the correct circumference of the Earth.
They explain the features found east of the Arabian Peninsula on the map, and that India, Sri Lanka (Taprobana), the Malay peninsula, and China were all known to exist in Ptolemy's time. Although their detailed shape was not known accurately.