Gaea is predominately (65%) covered by a single great ocean, plus a single mega-continent that runs from south of the equator to almost the north pole, with the expected wide range of climates and ecologies. There are archipelagoes and island clusters both near the continent and much further away. Not all of the world, (or even the continent), is considered “explored”. Short of direct knowledge imparted by a Power, the wide ranging eldarin explorers and mariners would be the best source of maps and such.
There are vast reaches that but seldom, or never, feel the tread of a boot or halfling’s sole. In earlier days, there were large regions densely populated by one or more of the People, with a network of routes on road and water connecting thousands of small towns and great cities. In these depopulated times, the sites of civilization are both fewer, and less tied to each other, while small barbaric bands wander the wild places between.