Gulliver says he will describe the country briefly. He travelled no more than two thousand miles round the capital. Even when the queen went with the king on his progresses, she went no farther.
The kingdom is a peninsula. To the north-east it ends in a ridge of mountains thirty miles high, impassable because of the volcanoes on top, and on the other three sides is the ocean. The coasts are so full of pointed rocks that there is not a single seaport. So these people have no trade at all with the rest of the world.
Gulliver leaves a word for the geographers of Europe. They suppose there is nothing but sea between Japan and California, and they are wrong, so they should correct their maps. He will gladly help them do it.