Helen's Tower, Clandeboye Estate, Bangor, Co Down, BT19 1RN

Helen's Tower is a four-storey, square-plan memorial tower in the Scottish Baronial style, dated 1848 and designed by the architect William Burn. It stands on an elevated site within Tower Hill Wood in the southern reaches of Clandeboye Estate, west of Conlig and north of Newtownards, rising above the tree canopy with full panoramic views of the estate and surrounding countryside. It is considered one of the two finest memorial towers in Ireland, the other being Scrabo Tower, and is a rare example of its type. The tower was completed and christened Helen's Tower in November 1850 by the first Marquess of Dufferin and Ava as a tribute to his mother, Helen Selina Sheridan, granddaughter of the playwright and statesman Richard Brinsley Sheridan, though the internal fitting out was not described as finished until October 1861.

Burn's original drawings, dated 1848 and showing the tower as executed, have survived. His design captions the building as "Gamekeeper's Tower", suggesting that may have been its original intended purpose. It has also been argued that the tower was built as part of expensive improvements to the Clandeboye Estate undertaken by Lord Dufferin after he came of age in 1847, partly to relieve the unemployment and destitution caused by the Famine. The tower first appears labelled on the second edition Ordnance Survey map of 1858, and is listed in Griffith's Valuation of 1856–64 as "Helen's Tower and land", with the building valued at £8 and the surrounding land of over 240 acres valued at £100.

The tower has been described as a product of twin mid-Victorian obsessions: with the revival of Romantic and historical building traditions, and with the raising of towers.

Externally, the walling is of random coursed rubble basalt with long-and-short quoins and a projecting plinth course. Sandstone is used for the string course and for detailing to the corbelled turrets. The roofing is principally flat asphalt, with natural slate over the turrets. Cast-iron rainwater goods are fitted, with square hopper-heads breaking through below parapet level and circular downpipes.

Windows are replacement timber casements set into single and bipartite sandstone surrounds with chamfered cills and reveals rising to an impost, and round arched heads with a keyblock over. The entrance is a triangular-headed, timber-sheeted door with modern ironmongery, screened by a heavy-duty iron security door, set into a plain sandstone porch with chamfered surrounds. The porch has a feathered stone hipped roof, a square datestone inscribed "1850" and initialled "D&A" (for Dufferin and Ava), encased by a label mould with figurative stops, and surmounted by a diminutive pediment.

The principal elevation faces south and is asymmetrically arranged. The ground floor is battered, with a single window on the right side at first floor level, a single window to the left at second floor level, and a bipartite window centrally placed at third floor level. The parapet has a dropped centre section. A corbelled bartizan to the left carries a single arrowloop opening and rises above coping level to an inward-curving conical roof, slated at the lower courses with a lead cap surmounted by a ball finial. A diminutive corbelled bartizan to the right serves as a chimney stack and is surmounted by various clay pots. The west elevation matches the south in its detailing, with a single centrally positioned window at ground floor level fitted with a security screen, matching window arrangements at second and third floor, and matching bartizans to either corner.

The north elevation is asymmetrically arranged and is distinguished by a four-storey round stair-tower projecting from the northeast corner. The window arrangement to the main part of the tower matches that of the south elevation. The stair-tower is terminated by a corbelled squared turret with a crow-step gable end and pitched roof. Round-headed arrowloop openings appear at varying levels up to corbel height, with slightly larger arrowloops embraced by a gablet breaking eaves level on the north and south faces and centrally on the east face, and a gun-loop at parapet level on the north face.

The east elevation is asymmetrically arranged. The porch entrance is located at the re-entrant angle between the main tower and the stair-tower. The porch has a single round-headed arrowloop centrally on its east face. A single window is located centrally at third floor level on the tower, and the chimney turret occupies the left side of the parapet.

The interior of the tower has a Gothic character. Its authorship has been debated: it may be the work of Benjamin Ferrey or of the architect Lynn, with Ferrey favoured by one authority. The tower contained grand apartments including a bedroom with a four-poster bed, a library, and a sitting room with a carved and diapered ceiling. Some work to the interior may have taken place around the turn of the 20th century, with surviving correspondence referring to proposed plans for decorative plasterwork and panelling. The tower subsequently became somewhat neglected in the early part of the 20th century and was described by Harold Nicolson, in his history of the Dufferin family also entitled Helen's Tower, as "mingling the living savour of an Irish bothy with the dead scent of closed rooms, of Victorian hardwood, of camphor and of decaying brocades." The tower was thoroughly restored in 1989 under the supervision of Colin Deane. More recently it has been leased to the Landmark Trust, who have carried out interior renovations to the ground and first floors with a view to letting the property as a holiday rental.

A manuscript notebook entitled The Book of Helen's Tower contains a collection of poems requested by or given to Lord Dufferin, some of which are engraved on the internal walls of the tower. The most celebrated is by Alfred Lord Tennyson:

"Helen's Tower here I stand / Dominant over sea and land. / Son's love built me, and I hold / Mother's love in lettered gold / Would my granite girth were strong / As either love, to last as long. / I should wear my crown entire / To and thro' the Doomsday fire / And be found of angel eyes / In earth's recurring Paradise."

Further poems were contributed by Robert Browning, Thomas Carlyle, Sir Edwin Arnold, Rudyard Kipling, Richard Garnett, and Wilfrid Scawen Blunt, some of them written after Helen Sheridan's death in 1867. Some years after the tower's inauguration, a small privately printed edition of The Book of Helen's Tower was produced, giving details of the inauguration ceremony and including a poem by Lady Dufferin to her son. The book concluded with three poems by Byron, Coleridge, and Thomas Moore, each dedicated to Lady Dufferin's grandfather, Sheridan.

The tower holds particular international significance as the direct inspiration for the Thiepval Memorial in northern France, which commemorates the men of Ulster who fell during the First World War and was erected by public subscription from Northern Ireland. The design of Helen's Tower was repeated at Thiepval on an enlarged scale because many soldiers of the Ulster Division camped and trained at Clandeboye before being deployed to France, and the tower would have been one of the last buildings they saw before being sent to the Somme.

The immediate setting of the tower has been somewhat compromised by recent levelling and the construction of a large car parking area at its base, bounded by a timber stake fence and security gate. The tower is accessed by a long curving road leading to this car park. Despite this, the tower remains well proportioned, retains much historic fabric of fine quality and craftsmanship, and continues to rise above the surrounding tree canopy.