Severndroog Castle: A Forgotten Tower, a Widow's Tribute, and London's Most Unlikely Landmark

Stand at the highest point of Shooters Hill in south-east London and the city falls away beneath you in every direction. To the north, the silver thread of the Thames. To the south, the wooded ridges of Kent. And rising from the canopy of Oxleas Wood, an extraordinary Gothic tower — three turrets, dark stone, sixty-three feet of silent ambition — watching over it all as it has done since the reign of George III.

This is Severndroog Castle. Not a castle in any military sense, but a folly — a monument born from grief, empire, and one woman's determination that her husband's name would not be forgotten. Its story stretches from the fortified coastline of western India to the boardrooms of the East India Company, from the birth of the Ordnance Survey to a twenty-first-century community rescue that brought a derelict shell back to vivid life.

A Commodore's Legacy

The man Severndroog Castle commemorates never saw it. Sir William James, 1st Baronet, died on 16 December 1783 — just months before the first stone was laid. Born in 1722, James had joined the Bombay Marine in 1747 and risen swiftly through the ranks: captain by 1749, commodore and commander-in-chief of the Bombay Marine by 1751. His defining moment came in April 1755, when he led a naval squadron against the island fortress of Suvarnadurg — anglicised as "Severndroog" — on India's western coast between Mumbai and Goa. The fortress belonged to the pirate chief Tulaji Angre of the Maratha Empire, and its fall was spectacular: British mortar fire destroyed the powder magazine, and the thousand-strong garrison tried to flee only to be intercepted by James's squadron and forced to surrender.

The victory made James's reputation. He returned to England a wealthy man, was elected a director of the East India Company in 1768, served as its deputy chairman and then chairman, was granted a baronetcy in 1778, and sat as Member of Parliament for West Looe from 1774 until his death. When he died, his widow Lady Anne James resolved to raise a monument equal to the scale of his achievement.

The Tower Rises, 1784

Lady James commissioned the architect Richard Jupp — surveyor to the East India Company — to design the memorial. The first stone was laid on 2 April 1784, almost exactly twenty-nine years to the day after the battle it commemorated. What Jupp created was striking and unusual: a Gothic tower with a triangular cross-section and hexagonal turrets at each of its three corners, rising sixty-three feet above the summit of Shooters Hill. On a clear day, the views from its battlements stretched across seven counties — a panorama that would prove to be more than merely scenic.

A Tower That Mapped a Nation

Almost as soon as the mortar had set, Severndroog Castle found a purpose Lady James could never have anticipated. General William Roy, the great military surveyor, recognised that Jupp's tower — perched at one of the highest points in London — offered a perfect triangulation station. Between 1784 and 1790, Roy used it as part of his pioneering trigonometric survey connecting the Royal Greenwich Observatory with the Paris Observatory. That work laid the scientific and institutional foundations for the Ordnance Survey, Britain's national mapping agency. Half a century later, in 1848, the Royal Engineers returned to the same vantage point to conduct a survey of London itself. A widow's memorial had become an instrument of science.

Decline and Rescue

For much of the twentieth century, Severndroog Castle stood open and enjoyed. Its Grade II* listing in 1954 acknowledged what locals had always known — that this was a building of exceptional interest. But listing alone could not pay for upkeep. By 1988, escalating maintenance costs had become insurmountable, and the castle was boarded up. For the next fourteen years it sat behind plywood and padlocks, slowly surrendering to damp, vegetation, and neglect. The tower that had once surveyed seven counties could barely be seen through the encroaching woodland.

The rescue, when it came, was a community effort. In 2002, a group of local campaigners formed the Severndroog Castle Building Preservation Trust with a single, stubborn objective: to save the building and open it to the public once more. The years that followed were a marathon of fundraising, planning applications, and sheer determination. The breakthrough came with a £595,000 grant from the Heritage Lottery Fund. Renovation work began in earnest in July 2013, and barely a year later — on 20 July 2014 — Severndroog Castle reopened its doors.

What Severndroog Preserves

Today, the restored castle is far more than a pretty shell. Its rooms tell the layered story of Sir William James, the East India Company, the Battle of Suvarnadurg, and the building's own unlikely journey from memorial to scientific instrument to derelict ruin to community landmark. The tower itself — Richard Jupp's extraordinary triangular plan, the hexagonal turrets, the Gothic detailing — is the primary artefact, a rare surviving example of an eighteenth-century commemorative folly in an urban setting. From the roof, visitors can still take in the panoramic views that attracted General Roy more than two centuries ago, stretching on clear days across the sprawl of London and deep into the counties beyond.

Why Severndroog Matters

Severndroog Castle sits at a remarkable intersection of histories. It is a monument to British naval activity in eighteenth-century India and a physical remnant of the East India Company's influence on London's landscape. It is a key site in the story of cartography and the birth of the Ordnance Survey. It is a case study in what happens when historic buildings are allowed to fall into neglect — and a testament to what passionate local communities can achieve when they refuse to accept that outcome. In the Royal Borough of Greenwich, a borough already rich with maritime and scientific heritage, Severndroog holds its own: a quiet, lesser-known counterpart to the grandeur of the Old Royal Naval College and the Observatory on the hill opposite.

The castle now operates as a visitor attraction and is available for private functions and events — a living building once more, sustained by the trust that fought to save it and the visitors who climb its spiral staircase to see what General Roy saw from its battlements.

Visiting Severndroog Castle

Severndroog Castle stands in Castle Wood, off Castle Road, Shooters Hill, London SE18, within the Royal Borough of Greenwich. The castle is managed by the Severndroog Castle Building Preservation Trust. For current opening times, event listings, and booking information, visit severndroogcastle.org.uk.

This article was partly inspired by old photographs and personal recordings that came to light when someone brought their family memories to be digitised — images of the castle in its boarded-up years, before the restoration, when the turrets disappeared behind ivy and the hill belonged to dog walkers and the occasional curious trespasser. It made us wonder what else is out there — in attics, shoeboxes, old cupboards — connected to Severndroog Castle. If anyone holds old media connected to this remarkable place, services like EachMoment can help preserve them for future generations.