However, upon this island is a round structure with a cone-shaped top that was built in 1821 by James Hughes to store food and provide shelter for shipwrecked seamen. Two much smaller islands, Garreg Allan (The Outer, Expelled or Furthest Stone, not visible by the naked eye from the shore, behind Ynys Dulas) and Ynys y Carcharorion (Prisoners' Island, nearer Traeth Dulas) are also present.
However, on this island is a circular structure with a conical top that was constructed in 1821 by James Hughes to store food and provide shelter for shipwrecked sailors. Two smaller islands, Garreg Allan (The Outer, Expelled or Furthest Stone, not visible from the shore due to its distance behind Ynys Dulas) and Ynys y Carcharorion (Prisoners' Island, closer to Traeth Dulas), are also present.