Coin of Flavius Gratianus c.375-383 AD, reverse

Parks & Gardens

The Diana fountain at Bushy Park

Bushy Park, London Borough of Richmond

An archaeological excavation and watching brief was undertaken at the cascade and lower pond in Bushy Park Water Garden, Upper Lodge, and was commissioned by The Royal Parks. The work was undertaken on an intermittent basis as part of a restoration and renovation project. The aim of the restoration project was to recreate the cascade's original, early 18th century form as accurately as was reasonably practicable given the constraints of the archaeological evidence. PCA was therefore contracted to undertake a series of three trial trenches prior to commencement of building work, in order to provide feedback to the design team.

Whilst some findings of former studies were confirmed, the larger trenches excavated enabled a more thorough assessment of the structure's stratigraphy. The results of the earlier work could therefore be placed in a wider context, necessitating some reinterpretation. After the trial trenches were completed, necessary demolition and building work on the cascade began. This was monitored on an intermittent basis.

The renovation became a dynamic process, as the watching brief yielded further evidence that would become key to the structure's final design.

The archaeology uncovered indicated that the structure had been partially rebuilt or modified at least eight times, from its construction in the early 18th century to the present day. Vestiges of its earliest phase were identified, enabling its original form and subsequent history to be partially reconstructed. Investigations were also carried out on the lower pond, which suggested the current feature is smaller and of a different shape to the original.

The Alnwick Garden, Northumberland

Now ten years old, The Alnwick Garden - a project initiated by the Duchess of Northumberland - has been described as Europe's most ambitious new garden. It occupies the site of the historic Alnwick Castle Gardens, which were derelict and largely forgotten before being transformed into The Alnwick Garden by the bold vision of the Duchess and the work of the celebrated Belgian garden designers Jacques and Peter Wirtz.

In 2000 PCA undertook a large scale archeological project to record the remains of the former gardens prior to the phased re-development. Two main areas were investigated by open area excavation and a programme of historic building recording was carried out in order to record historic structures that were to be removed to allow the Duchess’s scheme to proceed. To the north was the first excavation area, the site of the ‘lower’ original walled kitchen garden set out c.1760. Immediately to the south, occupying an extensive sloping area of ground, was the ‘middle’ garden, added c. 1860 during a major re-development by the 4th Duke of Northumberland.

The building recording documented a central ornamental pond, several ashlar terrace-retaining walls and three ruined former hothouses, along with the small pond and associated terrace of a former conservatory in the northern part of the site. In addition, earthwork survey was carried out on substantial 19th century earthworks enclosing the ‘middle’ garden.

The ‘lower’ garden excavation revealed traces of medieval soil horizons, overlain by evidence of successive garden layouts corresponding to the gardens of the 1st, 2nd, 3rd and 4th Dukes of Northumberland, and dating from the 1750s into the early years of the 20th century. The garden began to decline during the First World War, although allotments were established for intense vegetable growing during the Second World War and evidence for such activity was recorded by the work. The ‘middle’ garden excavation produced evidence of extensive landscaping prior to the setting-out by the 4th Duke of his mid 19th century formal garden, this the area now occupied by the centre piece of The Alnwick Garden, the incredible water displays of the Grand Cascade.

One of the notable findings of the archaeological project was that it clearly demonstrated the rare opportunity to employ technological developments directly as changes occurred, and - with particular reference to advancements in garden hothouse technology – it is clear that the historic walled garden at Alnwick remained at the forefront of design and technology for over 150 years, long before the site became an international symbol for innovative garden design in the modern era.

PCA returned to the site in 2004 to record the cellar of the former conservatory, known as the ‘old pavilion’, at the northern end of the original walled garden ahead of construction of a visitor centre and pavilion for The Alnwick Garden. The work suggested that the cellar was likely to date to the original construction of the conservatory, before 1772, and that above ground remains – recorded in the original work - represented a conservatory constructed in 1862. Various modifications to the cellar were noted, some of these reflected technological change, with at least two, possibly three, forms of heating represented.

Alnwick Castle Gardens before the archaeological work in 2000 (Alnwick Castle to the left, rear ground) Alnwick Castle Gardens before the archaeological work in 2000 (Alnwick Castle to the left, rear ground) Reproduced from 1867 Ordnance Survey® map Excavation and recording of the ‘middle’ garden of the 4th Duke of Northumberland (from the 2000 work) Furnace in the 2nd Duke of Northumberland’s garden (from the 2000 work) CAD drawings of the elevations of the cellar of the former conservatory (from the 2004 work)

Kensington Palace

PCA recently conducted a series of archaeological investigations in the grounds of Kensington Palace. One trench was dug on land adjacent to the east wing in a grassed garden area termed “Alice’s Tree”, three were opened in White Court, the supposed core of the Jacobean Palace, and a further two were excavated in the Rose Garden.

The earliest building on the site of Kensington Palace, created for George Coppin (Clerk of the Crown, was constructed between 1605 and 1620. He commissioned a villa-style Jacobean mansion, probably designed by land surveyor and antiquary John Thorpe. Internally, the building consisted of a long, central hall, orientated north-south, with rooms leading off to the east and west. This would become the core of Kensington Palace, around which later additions would be made. The building became the property of the crown during the reign of William and Mary, when the monarchs purchased it from Daniel Finch, 2nd Earl of Nottingham.

They commissioned a series of works designed to modernise the building, carried out under the instruction of Sir Christopher Wren (Surveyor of the King’s Works, 1669 to 1718) and Nicholas Hawksmoor (Clerk of Works, 1689-1715). Further improvements, renovations and repairs were made between the 18th and 20th centuries, the most extensive being those undertaken by William Benson (Surveyor of the King’s Works, 1718 to 1719) during the reign of George I (1714-1727) .

A layer of natural terrace gravel and sand, forming part of the Kempton Park sequence, was observed in the base of all six trenches. In Alice’s Tree Trench, a layer of clay sealed this, presumably dumped in order to artificially landscape the grounds between the 17th and 18th centuries. An 18th century drain, which once served the Palace’s eastern wing, truncated the layer.

The foundations of the Palace were observed in Trench 2 during excavations in White Court. They were composed of late 17th to 18th century masonry suggesting that, contrary to predictions, the Jacobean core did not survive in this location. A late post-medieval masonry foundation was also observed in Trench 3.

In the Rose Garden, undisturbed sequences of natural sealed by subsoil and topsoil were recorded.

In the grounds of Kensington Palace Trenches being excavated in the Rose Garden

Chiswick House, London Borough of Hounslow

An archaeological investigation was conducted at the site of The Arcade and Orangery within the gardens of Chiswick House. The archaeological investigation was undertaken prior to the restoration of part of the 18th century gardens to Chiswick House that includes the Arcade and Orangery.

The principal aim of the investigation was for the archaeological results to inform the design of the proposed recreation of the Arcade, to better reflect the original 18th century layout.

The investigation uncovered the original 18th century pebble mosaic floor of the Orangery, along with details of the foundations to the structure. A substantial part of a gravel path leading to the Orangery was revealed and recorded both in plan and section, which were of 19th century date.

Two 18th century statue bases that flanked the orangery, one supporting a statue of Hercules the other of a Gladiator, were revealed and recorded.

A linear feature, thought to represent an earlier 17th /18th century field boundary or planting line, possibly associated with the Jacobean Chiswick House orchards and predating the construction of the Arcade, was also uncovered and recorded.

The Orangery floor is cleaned prior to being photographed Part of the pebble mosaic floor of the Orangery One of the 18th century statue bases A replacement statue is hoisted onto its plimth The reconstructed Orangery floor