Please note that the Holme Fen Posts and the Holme Fen Nature Reserve are a Site of Special Scientific Interest (SSSI) and are managed by Natural England. While you are enjoying the area please take extreme caution not to disturb any plant or wildlife either deliberately or accidentally. Please observe the signs and keep to the marked paths at all times. Please leave only footprints. For more information about SSSI click here
In the early 19th century, the Nature Reserve at Holme Fen used to be the south-east shore of the Whittlesey Mere. In the 18th century, the Mere was said to be the second largest lake in England, but its size and depth had declined by Victorian times. The Mere had long been an important source of food and income for local people as well as being an outstanding place for wildlife. As people became more wealthy in the 18th and 19th centuries it was regularly used for recreation and boating. Due to rising population and potential profit from arable farming, however, all this was to change.
In 1851/2 the mere was drained after years of falling water levels, leaving peat rich arable land that was ideal for crops such as potatoes and wheat. Originally a team of men led by local landowner William Wells tried draining the land by digging ditches and drains hoping to remove the water via gravity, this was unsuccessful so a revolutionary Appold pump was purchased. This was first seen at the Great Exhibition held in The Crystal Palace at Hyde Park, London, in 1851. This pump was believed to be able to remove almost 70 tons of water a minute so within weeks the mere was drained. Therefore the value of the land went up considerably and landowners became richer.
Before draining the Mere, Wells buried a cast iron post in the ground with its base resting on the underlying clay, and the uppermost point at ground level. This was to monitor the shrinkage of the land as the peat beds dried out. Peat is almost 90% water, therefore when the mere was drained the water within the peat evaporated over time and resulted in the shrinkage of the land. Also, the peat blows away and evaporates to give off carbon dioxide when exposed to the air. All this is known as peat ‘wastage’.
The top of the Fen posts now stands approx 4 metres (15ft) above the ground. As you stand in front of the posts, you are standing at one of the lowest points in England some 2 metres (7 ft) below sea level.
The Great Fen Project aims to join Holme Fen to nearby Woodwalton Fen. In so doing this will create a new landscape of wetland and drier areas which will protect the important plants and animals found in the reserves today, encourage the spread of new species and enable people to enjoy and be involved as the land gradually changes from arable farming to grassland and fen. It may take many years as the Project can only proceed as landowners are willing to sell their land.
To log this Earthcache you need to post a photo of you and/or your GPSr by the posts with your log and email us via our profile on www.geocaching.com the answers to the following questions:
1. What covered most of the fens in around 4000BC ?
2. In what decade was the second post erected?
3. What was the peat soil known as that was left after the fens were drained?
If you are unable to take a photo please answer the following additional question.
On the left hand sign, who or what is in the photo of the post that was taken in the 1920s?
More information about Natural England is available here
More information on The Great Fen Project can be found here
We would like to thank the Senior Reserves Manager in charge of Holme Fen Nature Reserve for his assistance in developing this Earthcache.