A Response to the WHS Setting SPD

A Response to the Setting of the Stonehenge, Avebury and Associated Sites World Heritage Site Supplementary Planning Document (SPD)

Regarding the Recognition of Historical Agricultural Heritage, Specifically the Silage Tower

Date: June 10, 2025

Dear Wiltshire Council,

I appreciate the opportunity to submit my personal response to the draft Supplementary Planning Document (SPD) for the Setting of the Stonehenge, Avebury and Associated Sites World Heritage Site (WHS). I commend the SPD’s robust framework for protecting the Outstanding Universal Value (OUV) of this globally significant landscape, recognised by UNESCO since 1986. However, I believe the SPD could do more to acknowledge the historical agricultural heritage of the WHS, particularly the silage tower near the Stonehenge Visitor Centre. While the SPD currently identifies this structure as a visual detractor, it overlooks its potential significance as a rare example of 20th-century agricultural heritage, which I believe deserves recognition and thoughtful consideration.

Background on Silage Towers

Silage towers have played an important role in agricultural history, as highlighted in Historic England’s guidance on farm buildings (Historic England, 2014). First introduced from the United States in 1901, these airtight structures were designed to store freshly cut grass for conversion into silage, a key innovation that provided farmers with a reliable supply of fodder. Their use became widespread after World War II, marking a significant shift in farming practices. However, intact pre-1940 examples are now rare, especially those constructed in concrete. The silage tower at grid reference SU 10207 43450, appearing on the 1939 Ordnance Survey map, located on the Lesser Cursus ridgeline near the Stonehenge Visitor Centre, is one such rare survivor, adding an important layer to the WHS’s historical narrative.

Context within the WHS

The Stonehenge and Avebury WHS is rightly celebrated for its prehistoric monuments, but the landscape also reflects centuries of agricultural activity. The silage tower, though modern in comparison to Neolithic and Bronze Age features, embodies the agricultural heritage that has shaped the WHS’s rural character. Its presence illustrates how farming practices have coexisted with archaeological significance, offering a broader understanding of the site’s evolution. Recognising such features supports the WHS Management Plan’s aim to enhance the site’s historical context.

Concerns with the SPD

The SPD describes the silage tower as a “prominent abandoned modern feature” that negatively impacts the WHS’s setting due to its visibility from several viewpoints, including Robin Hood’s Ball (Page 126, S-VP14; Page 147, Section 5.9). However, the SPD does not offer specific recommendations for addressing this structure, nor does it acknowledge its potential historical value. I am concerned that this omission could result in the prehistoric OUV being prioritised at the expense of more recent heritage, potentially leading to decisions that undervalue or remove significant agricultural features without proper assessment.

Recommendations

To ensure the silage tower’s historical significance is properly integrated into the WHS’s management, I propose the following amendments to the SPD:

• Acknowledge Agricultural Heritage: Add a subsection to Section 2.0 (Page 20) recognising the historical importance of agricultural structures like the silage tower. This would reflect the WHS Management Plan’s goal to “maintain and enhance the WHS by including significant archaeological features” (Page 18), extending this consideration to post-prehistoric heritage.
• Assess Historical Significance: Amend Section 3.0 (Page 41) to require Heritage Impact Assessments (HIAs) that evaluate the historical and architectural significance of agricultural structures, particularly the silage tower. Given its rarity, as noted by Historic England, research involving agricultural historians could determine its age and context, potentially justifying its inclusion in the WHS’s historical inventory.
• Enhance Visitor Interpretation: Update Section 2.6 (Page 35) to incorporate the silage tower into interpretive materials, such as signage or digital resources, to highlight the WHS’s agricultural history. This would enrich visitors’ understanding of the site’s evolution from prehistory to modern times, aligning with the Management Plan’s focus on education (Page 17).
• Explore Preservation Options: Revise Section 5.9 (Page 147) to consider preservation or adaptive reuse of the silage tower, balancing its historical value with the WHS’s visual integrity. For example, stabilising the structure as an educational exhibit could maintain its heritage significance without compromising OUV, subject to HIA evaluation (Page 44, Section 3.2).

Conclusion

The Stonehenge and Avebury WHS is a dynamic landscape shaped by millennia of human activity, including agriculture. The silage tower, though currently seen as a detractor, is a rare and significant feature of the site’s 20th-century agricultural heritage. By acknowledging and preserving such elements, the SPD can present a more holistic narrative of the WHS’s history. I urge Wiltshire Council to adopt these recommendations, ensuring that the silage tower is celebrated as part of the site’s rich tapestry. I look forward to further collaboration during the consultation process.

Yours sincerely,

Tim Daw
All Cannings, Wiltshire
June 10, 2025

References

• Historic England: National Farm Building Types, 2014
• Setting of the Stonehenge, Avebury and Associated Sites World Heritage Site (Draft for Public Consultation), Wiltshire Council, 2025