The first of six disks in the T2 (“The Continents”) series shows the head of the Great Sphinx of Giza, situated on the Giza Plateau adjacent to the Great Pyramids of Giza on the west bank of the Nile River in Egypt.
(Image: © Copyright Gregory Williams (Flickr) and licensed for reuse under Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic (CC BY-NC-ND 2.0))
The Continent is therefore Africa. The letter in the square below is “A”, and we’ve now got three of the six letters. In disk order, these are “A__TR_”. That doesn’t look promising as a word, unfortunately.