Lakenheath Fen is an RSPB reserve in Suffolk, about fifteen miles north-west of Bury St Edmunds, The surrounding landscape is flat and tends to monotony, so the eye is often drawn upwards to the big East Anglian skies. The reserve itself is a remaking of this already drained, reclaimed and completely man-made environment. What looks like the marshy hiding place of Hereward the Wake or some folk memory of the Mesolithic Eden of Doggerland, was a carrot farm until 1996.

Since then the RSPB have dug channels and lagoons, planted trees and reed-beds, marked out paths and added a hide for bird-watchers and a few of what it calls viewpoints. These are open wooden structures, each with a small thatched roof and a wooden dividing partition, on either side of which there are benches built in. They look like rural bus shelters. I spent a Saturday night in late April trying to sleep in one so as to wake up early enough to record the dawn chorus

Joist Fen is at the western end of the reserve. Close by the viewpoint is a small pond, and in the recording on this page you can hear the sounds of ducks going about their affairs on it. Warblers and small, unseen birds lurked and chattered in the surrounding reed-beds and in small, scrubby bushes. A bittern called from time to time, sounding like someone blowing over the wide top of an old milk bottle. A distant machine tone came from somewhere to the south-east: perhaps from an agribusiness factory. It continued into the small hours.

A thin layer of cloud condensed and the lights of towns threw pools of dull orange phosphorescence onto its underside: Ely to the west, perhaps Cambridge far to the south. The tumbling silhouettes of bats appeared and disappeared, then an owl, recognisable from its flat face in profile, flying to within fifteen feet, then again at half that distance, before leaving the shadow-play with a shriek.