Garrison Walls — Historic Defences on St Mary’s

A Coastal Stronghold Overlooking the Isles of Scilly

On the western edge of St Mary’s, the Garrison Walls form one of the most complete sets of coastal defences in England.
Built from the 16th century onward, they protected the Isles of Scilly from naval threats.
Today, their bastions, gateways, and sea views make them a major historic site.

It’s a large defensive complex surrounded by coastal scenery.

Centuries of Island Defence

The fortifications began under Elizabeth I and expanded through the 17th and 18th centuries.
They defended a strategic harbour that controlled routes to Cornwall and the Atlantic.
Therefore, the Garrison became an important military site for the Crown.

Key features include:

Curtain walls

Gun batteries

Gateways

Lookout points

Dry ditches and ramparts

In addition, later improvements strengthened the entire perimeter.

Exploring the Garrison Walls
1. The Curtain Walls

The long stone walls encircle the Garrison headland.
Walking beside them reveals their scale and design.
In addition, the path offers views across the sea and harbour.

2. The Bastions and Batteries

Large, angled bastions project from the walls.
These structures once held guns that defended the approaches to St Mary’s.
Moreover, many of the platforms remain clearly visible.

3. The Main Gate and Guardrooms

The gateway leads into the Garrison from Hugh Town.
Its thick walls show the strength of the original defences.
Furthermore, nearby structures hint at daily military activity.

(Learn more at the English Heritage page for Garrison Walls.)

Military History Across the Centuries

The Garrison played roles in:

Elizabethan coastal defence

The English Civil War

18th-century fortification improvements

Later adaptations linked to gunpowder and artillery changes

Because of these long phases, the site shows clear layers of military development.

Walks and Coastal Views

The circular wall walk is one of the best routes on St Mary’s.
Visitors can enjoy views toward Tresco, Samson, and the open Atlantic.
In addition, the paths link easily with Hugh Town and surrounding trails.

Popular walking combinations include:

Garrison circular walk

Paths to Peninnis Head

Walks around Hugh Town harbour

Routes toward Porthcressa Beach

For more island history, see our guides to Dunstanburgh Castle and Corfe Castle.

Wildlife and Landscape

The Garrison headland supports coastal plants, seabirds, and seasonal wildflowers.
Because the area is open and windy, conditions change quickly.
The combination of cliffs, grass, and sea views adds to the site’s character.

Visiting the Garrison Walls
How to Get There

Location: St Mary’s, Isles of Scilly

Access: Short walk from Hugh Town

Boats: Regular services to St Mary’s from mainland Penzance (seasonal)

Opening Hours & Admission

Open daily

Free access

Facilities

Cafés and shops in Hugh Town

Level walking paths around parts of the Garrison

Information panels at key points

Nearby Attractions

Star Castle — 16th-century fortress within the Garrison

Hugh Town — Shops, beaches, and harbour

Peninnis Head — Coastal headland with granite formations

Tresco Abbey Garden — Subtropical gardens on nearby Tresco

Together, these form the Isles of Scilly Heritage & Coastal Trail.

Why Visit the Garrison Walls?

The Garrison Walls experience offers:

Extensive coastal fortifications

Wide views across the Isles of Scilly

Easy, scenic walking routes

Free access year-round

Whether you enjoy military history, sea views, or island walks, the Garrison Walls are one of the most rewarding historic sites on St Mary’s.
It’s not just a fortification — it’s a complete defensive system shaped by centuries of coastal threats.