King Charles’s Castle — A Coastal Artillery Fort

A Ruined Fort Overlooking the North Coast of Tresco

On the island of Tresco, King Charles’s Castle stands above the coastline with outstanding sea views.
Built in the mid-1500s, the fort was designed to protect the Isles of Scilly from naval attack.
Today, its ruined chambers and raised setting make it a memorable walk.

It’s a small but dramatic coastal fort.

Tudor Military Origins

The castle was built during the reign of Edward VI.
Its purpose was to defend the channel between Bryher and Tresco.
However, its height made gunnery difficult, and it was later replaced by the lower Cromwell’s Castle.

The fort originally featured:

Gun chambers

A long, narrow firing gallery

Thick stone walls

Elevated firing positions

In addition, later collapse left the ruin seen today.

Exploring King Charles’s Castle
1. The Gun Rooms

The interior includes a row of artillery chambers.
Visitors can walk through the narrow spaces used by gunners.
In addition, the openings show how the guns were aimed at the sea.

2. The Courtyard and Ruins

The central area contains broken walls and open views.
This space allows you to understand the castle’s shape.
Moreover, the ruins create strong photographic angles.

3. Coastal Views

From the castle, you can look across Bryher, Cromwell’s Castle, and the open sea.
These views highlight the strategic importance of the site.
Furthermore, the coastal walk to the ruin is one of Tresco’s highlights.

(Learn more at the English Heritage page for King Charles’s Castle.)

Walks and Nearby Sites

Visitors often combine the fort with:

Cromwell’s Castle

King James’s Battery

Tresco Abbey Gardens

Coastal paths around Tresco’s north coast

For more fortifications, see our guides to Garrison Walls and Dartmouth Castle.

Visiting King Charles’s Castle
How to Get There

Location: Tresco, Isles of Scilly

Access: Footpath from New Grimsby

Ferry: Boats between the islands

Opening Hours & Admission

Open daily

Free access

Facilities

No facilities at the site

Shops and cafés in New Grimsby

Coastal walking paths

Why Visit King Charles’s Castle?

The King Charles’s Castle experience offers:

A dramatic cliff-top fort

Clear Tudor artillery features

Beautiful island views

Free, open-air exploration

It’s not just a ruin — it’s a fort that shaped the military landscape of Tresco.