This book describes the geography and early mapping of Offaly (known as King's County between c. 150 and 1920) with particular reference to the huge manuscript map of the county made by William Larkin. The version reproduced here in atlas form was made in 1809 at the request of the newly formed Bogs Commissioners, and was used to guide their engineers.

Among other features, it provides a unique record of the landscape, including roads, settlements and bogs, in the early 19th century.