Scheduled MonumentsWalesSully Island, "Danish" Fort
Prehistoric · Hillfort

Sully Island, "Danish" Fort

Wales
Cadw SAM GM035
Period
Prehistoric
Site type
Hillfort
Broad class
Defence
Nation
Wales
Boundary

Scheduled area

© Mapbox · © OpenStreetMap contributors · Boundary data © Cadw

Overview

History & significance

Sully Island "Danish" Fort is a prehistoric hillfork located on Sully Island in the Vale of Glamorgan, Wales. The site comprises a defensive enclosure defined by substantial earthwork banks and ditches, though its precise dating and chronological assignment remain matters of scholarly discussion. The popular designation as a "Danish" fort reflects historical interpretation rather than confirmed Viking-period occupation, and the monument is now understood more broadly as a prehistoric fortified settlement. The site represents an important example of Iron Age or earlier defensive architecture in the Vale of Glamorgan, though full archaeological investigation would be required to establish its exact chronological phase and functional significance.

Sully Island, "Danish" Fort is a scheduled monument protected by Cadw under reference GM035. View the official record →

About this monument

Questions & answers

What is Sully Island, "Danish" Fort?

Sully Island "Danish" Fort is a prehistoric hillfork located on Sully Island in the Vale of Glamorgan, Wales. It is designated a Scheduled Ancient Monument by Cadw under reference GM035.

What period does Sully Island, "Danish" Fort date from?

Sully Island, "Danish" Fort dates from the prehistoric period, and is classified as a hillfort. It is one of over 32,000 scheduled monuments protected across Britain.

Who is responsible for protecting Sully Island, "Danish" Fort?

Sully Island, "Danish" Fort is a Scheduled Ancient Monument, legally protected by Cadw — the body responsible for designating and safeguarding heritage sites in Wales. The official designation reference is GM035.

What other scheduled monuments are near Sully Island, "Danish" Fort?

Several scheduled monuments lie within 10 km, including St Mary's Well Bay Pillbox (0.8 km), Anti-aircraft and Coastal Battery West of Lavernock Point (1.2 km), Middleton Moated Site (2.5 km).

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