Roundwood Promontory Fort

Overview

Roundwood is a rare example of a Late Iron Age (around 2350-2000 years ago) promontory fort, built on a river rather than a coastal site. Situated between Cowland’s and Lamouth creeks, the monument juts out into the beautiful River Fal, hidden amongst a post-medieval plantation and extensively managed estate. The site has seen significant changes over the centuries, with the first quay being built in the 18^th century, leading to two hundred years of industrial activity across the site, to practice trenches dug during World War Two in preparation for the D-Day landings.

The impressive earthworks at Roundwood consist of two sets of concentric banks and ditches across the narrow neck of the promontory. The ramparts survive well, still visible in the landscape and partially fossilised in later boundaries and hedges. Beyond the ramparts is an oval enclosure on the raised interior measuring approximately 95m east-west by 60m north-south, with steep sides down to the waters edge. These earthworks make it a highly defensible site typical of Late Iron Age promontory forts along the coast of Cornwall with access tightly controlled across the causeways still used today.

As you explore the site today, over the causeway through both sets of outer ramparts, you are using the same entrance as the people who built and defended this stronghold thousands of years ago. The entrance would have been strategically placed, allowing controlled access into the heart of the fort and the resources stored there. Promontory forts or cliff castles found along the Cornish coast served multiple purposes in the Iron Age, with their likely functions evolving over time:

• Defence: A fort such as Roundwood is a good place to store surplus food and stop rival tribes from raiding and stealing resources like animals or metal.
• Control and exploitation of a resource: Roundwood may have been built to control use of the river for communications and food like fish and mussels.
• Trade: The Fal provided an opportunity for goods to be transported more quickly, easily and further afield
• Status: A show of status and wealth for a tribal leader who could gather enough people and resources to construct such a monument
• Ceremony and ritual: The site may have hosted gatherings, rituals, and negotiations between tribes.

Roundwood Promontory Fort was part of Cornwall National Landscape’s A Monumental Improvement Project, which aimed to ensure that 40 scheduled monuments across Cornwall National Landscape were better protected, identified and enjoyed by a wider range of people. Between 2022 – 2025, the Project delivered conservation repairs, installed new heritage interpretation signage, ran a range of community volunteering events and developed new website resources. The Project was primarily funded thanks to The National Lottery Heritage Fund, with support from our other partners – Cornwall Council, Historic England, The National Trust, Cornwall Heritage Trust and Cornwall Archaeological Society.

Historical Significance

Although Roundwood is peaceful today, in the 18th and 19th centuries it was a hive of industrial activity. The quays were built around 1760 by Thomas Daniel to serve the booming tin and copper mining industries of Kea and Gwennap – at one time declared the richest square mile in the Old World- allowing the import of coal for steam engines serving the mines locally and copper smelting operations on the quayside. Later, in the nineteenth century as the price for Cornish copper dropped, it was no longer economically viable to smelt ores at the site, and the quay was used to export the copper ore to Wales to be smelted.

Before the railways, mule trains would bring ore from the mines onto the quay along the improved road to be loaded on to vessels of up to 300 tonnes which could moor at the quay even at the lowest tides.

Eventually the development of the Redruth and Chasewater railway with links to ports at Devoran and Point superseded the quay and its use declined. Later in the 19^th century, several other industries took place on the quayside, including boat building, a depot for coal, and a lime kiln. All this industry left its mark on the promontory. A series of leats (water channels) were dug bringing water to a reservoir on the site, making use of the original Iron Age ditches associated with the fort, and several quarries and a sawpit can still be seen today.

As the main industrial use of the quay declined, the site was incorporated into the Trelissick estate’s wider pleasure landscape and much of the plantation dates from this period. The promontory is shown clear of woodland on the 1st edition Ordinance Survey map of c 1813 but was shown as planted on the 1821 version. The 1842 Tithe Apportionment recorded the area as coppice wood, and geophysical survey results suggest significant management and alteration of the trees has occured since then.