what was the whole extent of the Kingdom of brobdingnag?

"The Country described. A Proposal for correcting modern Maps. The King's Palace, and some Account of the Metropolis. The Author's way of travelling. The chief Temple described."

Gulliver spends a great deal of time describing the landscape of Brobdingnag, the palace that he now lives in and his manner of traveling in a small traveling box designed especially for him. He also sees and describes the largest temple in Brobdingnag, which he does not find impressive in its size.