Voyages to the House of Diversion 
Seventeenth-Century Water Gardens and the Birth of Modern Science



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You who enter here, study every detail
And then tell me if all these marvels
Are made for deceit or for art.

Inscription from the Sacro Bosco, Bomarzo attributed to Pier Francesco 'Vicino' Orsini (1523 - 84)


It's published!
Available now from Oxbow Books


The Original Research Outline

Easter, Down in the Jungle Where...     May - The Kingdom of Cobbles
June and July - Another Big Dig       September - Our Weekend of Living History

Closing the Circle... or rather the Octagon

March, April, May - In and Out of Lock-down       June, July, August - Here, There, Everywhere    September - History Lives!


July - Back in Business       August - The 'Big Dig' Revisited        September - On into the Autumn

October - The Flood and its Aftermath     November/December - Ticking Over

February - Stars and Snowdrops Plus     March - West Side Story   April - More Pots and some Glass

May/June - New faces, New Challenges     July/August - After the Digger     September/October - A Roman Holiday and Other Interludes

November/December - Closing down and Opening up

January - The Big Tidy Up and a Recap    February - Opening it all up   March - Opening it up even further

April - Drying Out
   May - Sun, Sun, Sun, Rain   June - A Very Polygonal Month

July - The Month Goes Potty   August - Onto the North West Face   September -The View to the West

October - The Rising Tide     November - The West End

January to April - Picking up the pieces   May to July - A walling we will go....

April - Down in the valley below     May - The Lower Sluice

The second half of 2016 saw much of our efforts directed to the Cropredy Churchyard Dig
so it wasn't until the start of 2017 that we really got the ball rolling again at Hanwell

January - Hanging Out With Builders     February - So much to do so little time...   March - The North European Dimension

April - Revisiting Old Favourites     May - Playing catch-up     June - Preparations    July - Big Dig II

August - Working with the National Trust     September - The Italian Job    October - A Passage to India

November, December 2015 and January 2016 - Typing, Typing, Typing

January - Getting the Ball Rolling Again   February - Building and Demolition   March - The Race Against Spring

April - Moats and More  
May - Walls, Walls, Everywhere   June - Two Weeks in Tuscany

July - Preparations Go On Apace   August - From the Remarkable to the Extraordinary... plus the BIG DIG

September - Fall out and Follow up to the BIG DIG   October - On into the Autumn
   November - Wrapping it up for the Winter  December  - Nothing

January - The Project Begins         February - Clearing the Decks      March - A Race Against Time 
April - The Pace Quickens             May - A Month's Worth of Rubble     June - Return to Goose Island

July - Operating on Two... er Three Fronts.      August - Too Much Archaeology?      September - A Sluice Too Far

October - Oxford Beckons   November - Hands on Enstone  December - Office Work


The Castle
Thomas Baltzar - a musician in residence
The Cope Family Tree
Sir Anthony's Clock
Sir Anthony's Other Clock ... the watery one
Sir Anthony's Portrait
The Enstone Marvels
Robert Plot and Hanwell
'The Country of the Heart' - More Ideas on Mapping
St. Peters Church - A Surfeit of Scratch Dials
The Cope Family's Brush with Shakespeare
Renaissance Water Gardens in Tuscany
Hydraulic Engineering at Chantilly
Hesdin, the Quest for the Marsh Pavilion
Renaisance Water Gardens In Lazio and the Sacro Bosco
Glimpses of Indian Gardens and Hydrology

The Pondyards, Gorhambury, Francis Bacon's water gardens
John Claridge and his 'Shepherd's Legacy'
Polygons in Gardens
Garden Pots of the Period

Project Maps
Project Plans
Small Finds

Back to Polyolbion Archaeology

The work at Hanwell is largely staffed by volunteers, offers of help are always welcome and full on the job training is provided. If you would like to lend a hand get in touch, email me at

DISCLAIMER. Please feel free to make use of this site ( with appropriate acknowledgments of course) but please also remember that these are working notes of a project's progress and much of the content is speculative and occasionally pure whimsy... be critical in what you accept.

Castle tower from the west                                                                         Upper Pool and island from the east                                                                Tower and south range from the north

The castle and park at Hanwell, Oxfordshire constitute a remarkable site or rather series of sites which demonstrate enormous archaeological potential. The current owners of the larger part of the grounds have, over the past few years, both conserved and developed the park, creating an extraordinary community observatory and instituting the popular series of 'Stars and Snowdrops' open days. The existing castle was begun in 1498 when the manor, previously held by the de Vernon family came into the possession of William Cope, treasurer to Henry VII and is the area's earliest brick building. The park underwent considerable development in the late sixteenth and early seventeenth century to the point where its celebrated water gardens were visited by royalty and commented on by Robert Plot in his Natural History of Oxfordshire of 1677.
Here is his account and if this is hard to imagine here is an illustration from the same work of what surely must have been a similar feature from Enst

Hanwell Hanwell

plot Plot

All of this suggests a Jacobean garden of some sophistication and enormous technical interest. Fortunately from the point of view of the archaeologist this represented the apogee of the site's development and from then on it appears that only minor works were carried out in the park. Three quarters of the castle were demolished around 1770 and the surviving portion and the outbuildings became a farm. Following extensive restoration in the  twentieth century the complex was divided into a series of residences. In fact the full story of the garden's development is likely to be much more complex and to reflect this I have started to compile a time line to link it all together.


Now, thanks to the activities of such 'improvers' as Lancelot (Capability) Brown, the number of intact gardens from the seventeenth century is vanishingly small and although the surface remains from the period are limited at Hanwell one can expect the archaeology to be relatively intact so we have here, through a process of detailed mapping and some small scale excavation, the potential to recreate, at least on paper, a great Jacobean garden. More specifically the kind of water powered 'special effects' seen at Hanwell were a distinctive feature of many gardens of the period yet details of the technology remain comparatively little known. A careful examination of the site could go someway to remedying this.


To help with seeing the big picture below are the earthworks redrawn from the 1900 map together with the reconstructed outline of the castle dropped in place. Running the cursor over the map will insert the contour lines. For me the obvious thing that this map reveals is the strong east - west axis of the arrangements. The entrance front to the castle is to the west but passing through the courtyard takes you out to a level area to the east where we could perhaps expect formal parterres and the like.  Beyond the possible site of the formal gardens we have the huge drop down to that part of the park which contains the Lady Pool and as we later discovered the water parterre beyond that further elements in the chain of large ponds. Now surface indications can be misleading but  the prediction was that the area around the Lady Pool was not a single large pool but was modeled to create the 'theatre of water' so in effect we should read it as a sunken water garden with, of course, more than sufficient head of water from the Upper Pool to power any number of special effects.


Late in 2012 some preliminary work was carried out in order to prepare an appropriate research plan for the work we proposed to undertake. However, even at an early stage a number of key questions presented themselves:
  • What was the nature of the earlier medieval manor and to what extent do the visible landscape features have their origins pre-1498?
  • Where were the original boundaries of the park?
  • At what date was work  begun on the Jacobean 'special effects'?
  • What remains of the various hydraulic devices and other garden features from the period?
  • Is it possible that the 'sunken garden' could have had its origins as some sort of grotto?
  • Where were the 'industrial' elements of the park located and what was their relationship with the more picturesque elements of the gardens?
  • What was the impact of the eighteenth century demolition of the castle on the surrounding landscape?

One of the best ways to get a grip on the scale of the undertaking is to consider what similar gardens, in their entirety would have looked like. My favourite image - and there are not a lot to choose from - is this extraordinary painting of a bird's eye view of the gardens at Llanerch Hall, Denbighshire by an anonymous artist around 1662.


Prospecting and Preparation

After an initial meeting with the owners of the larger part of the gardens in March 2012 we were treated to a grand tour of the grounds during which various improvements, including planting and pathways, were pointed out with some enthusiasm. The owners also shared with us their considerable knowledge of the historic development of the grounds and indicated a number of archaeological features that they were aware of. Naturally the potential site of the House of Diversion was bound to be a draw and following the purchase of a two person inflatable dingy an initial expedition was mounted to check on surviving remains on the island.

Land is sighted.

Although the margins of the island were rather overgrown, making an approach quite difficult, the centre was comparatively clear under the shade of a large Scots Pine. There were a number of loose blocks of stone round the perimeter of the island and one or two architectural fragments scattered amongst the undergrowth. The main feature was a sunken area roughly 2 metres by 4 metres which was lined with rough stone blocks. A local informant reported that this was known as Sir Anthony's Bath and that formerly steps had been visible going down into it. It will probably be worthwhile taking some secateurs over to cut back some of the more invasive growth which is clearly damaging the structure. We have also been taking some initial photographs of the earthworks and other features while the surrounding vegetation is still fairly close to the ground.

Architectural fragments                                                                 Sir Anthony's Bath                                            Steps made from architectural fragments                                   Collapsed revetment to island

Given the very specific statement in Plot about the location of and effects achieved within the House of Diversion a pressing question is how the various fountains were powered. There is a small pond to the west but it is unclear as to whether or not this would be high enough to achieve the desired effects. Equally there could have been some kind of pumping mechanism, possibly powered by a waterwheel utilising the outfall to the north-east. Here are some examples illustrated in roughly contemporary sources.

pump               Pump

Lots of interesting questions raised by these images, not the least being what would be left of them in the archaeological record?  Hmm...

How it all looked... at the beginning.


Sluice below the Lake from the east                                                            'Sunken Garden' from the east                                                Terracing east of the Observatory from the east