Aerial reconnaissance and photography are of great importance in the study of the early history of Fenland and the surrounding country, conditions often being A very suitable for this method of investigation. A vast amount of information which can be recorded easily by air-photography, would only be obtained with the greatest difficulty, if at all, by field-work on the ground. The present paper is a brief record of observations made while flying over the fen basin during the course of duty. Unfortunately photography was not practicable, but systematic notes were kept of everything observed. Further work should reveal much more.