History

The lighthouse was built to mark the north entrance to Menai Strait, and the passage between the two islands, in 1835-38. It was designed by James Walker, consultant engineer to Trinity House. The lighthouse was manned until 1922 when it was automated and converted to gas power. It was converted to solar power in 1995 and solar panels fitted to the gallery. The gas power equipment remains on station.

Exterior

Ashlar, painted in broad bands of black and white. A circular tower 96 feet high (29.26m), on a stepped base, stepped in height at the half-way point, and with crenellated parapet corbelled out; cast iron lantern with conical roof surmounted by ball finial carrying arrow weather vane. Doorway in lower stage above the stepped plinth with Trinity House arms in relief above it, and small windows aligned with it in upper stages, which also have other intermittant windows. All windows are small-paned sashes, the openings apparently originally triple glazed. Lantern has grid of glazing bars, obscured on the landward side. One fog warning bell is suspended from the parapet. 'No Passage Landward' in large painted letters facing to either end of the strait.

Interior

Basement in the stepped plinth of the tower holds water tanks which were designed to receive rainwater gathered on the roof. Store room to ground floor, with shallow domed ceiling. Enclosed stone stair winding against the external walls. First upper level has former keeper's living room, wth built-in dresser, cast iron range (with enriched ironwork), pump and sink. Single rooms on each of the two levels above each retain small decorated cast-iron fireplaces. The original curved panelled doors remain throughout. Service room at top level below lantern has inscribed stone, 'Except the lord build the house....Psalm MCXXVII', and cast iron baluster to stairway to lantern. Fixed lens of first order catadioptric type, carried on a cast-iron platform which supports the braced cast-iron base of the optic.

Reasons for Listing

A remarkably complete early C19 lighthouse, which is of particular note for the exceptional survival of many of its original internal fittings.

External Links

• Cadwr Listing
• Trwyn Du Lighthouse at Wikipedia
• Wikidata Q1324554

External links are from the relevant listing authority and, where applicable, Wikidata. Wikidata IDs may be related buildings as well as this specific building. If you want to add or update a link, you will need to do so by editing the Wikidata entry.

Recommended Books

• 
  Lancashire: Manchester and the South-East (Pevsner Architectural Guides: Buildings of England)
• 
  Suffolk: East (Pevsner Architectural Guides: Buildings of England)
• 
  Essex: Buildings of England Series (Buildings of England) (Pevsner Architectural Guides: Buildings of England)
• 
  Listed Buildings, Conservation Areas and Monuments
• 
  Drawing up a Local Listed Building Consent Order: Historic England Advice Note 6
• 
  The Listed Buildings and Other Principal Structures at the Royal Gunpowder Mills Waltham Abbey