Started work on the town of Downham Market, a half hour train ride north of Cambridge. Downham is about 7,000 people (well, 2001 census, so it's probably more now), so one or two more sessions should do it - though I got a bit side-tracked this time away from the endless bungalows of the southern outskirts of the town, into Ryston Hall estate and related hamlet, Fordham hamlet (where I got lost among farm tracks which didn't go where I expected) and mainly the delightful village of Denver which among other things has a working windmill with a welcome tea-room-cafe for a hot afternoon and the Denver Sluice complex (south west of my marker). That is a major piece of flood and water engineering where the tidal River Ouse and the parallel major flood relief drain out to the Wash are linked to the southern river network along the Bedford levels. There's a broad canal called the Cut Off Channel which according to the signs used to drain into the Relief Channel through one of the three huge sluices but has now been closed and the flow reversed so that water runs many kilometres south east to Barton Mills near Mildenhall where it is pumped through a 40km tunnel and on to Essex to quench the thirst of its inhabitants. There's also a deep lock in the middle of the complex to carry boats from the upper river into the Relief channel - though curiously there's no connection into the Bedford rivers - you'd have to go down to Ely and across to Earith to get back to the bottom of the western sluice.