Seaport Lodge, Portballintrae, Bushmills, Co. Antrim, BT57 8SB

Seaport Lodge is a detached Georgian house built around 1770, prominently situated on the western tip of the bay at Portballintrae. It is one of the earliest surviving examples of a bathing lodge in the district and one of the most architecturally and historically significant buildings in the area. It has important connections with the Leslie family and group value with the former land steward's house and stables at Beach Park nearby.

The building is symmetrical across three bays, two storeys over a partially exposed basement, with a central bow bay to the front. The plan is rectangular, with a two-storey bow bay to the east front, single-storey bow bays to the north and south, and a two-storey return to the rear. The roof is hipped and covered in natural slate. Rendered chimneystacks rise from a balustraded parapet with piers topped by square pinnacles. Parapet gutters and cast-iron downpipes serve the rear elevation.

The external walls are finished in painted ruled-and-lined render and roughcast render, plainly detailed and set on a stepped plinth. A continuous string-course runs between the floors. The cornice is moulded and sits above a large dentilled, dog-tooth and fluted frieze. All windows are currently boarded over. They are framed by full moulded architraves; the first floor windows are square-headed, while those at ground floor are three-staged, full-height Venetian-style windows with heads springing from semi-engaged columns with fluted capitals.

The symmetrical east front has the two-storey bow entrance bay at its centre, flanked on each side by bays containing a square window above a Venetian-style window. The entrance doorway has a double-leaf three-panelled timber door with brass furniture, surmounted by a boarded fanlight, and flanked by panelled pilaster jambs with fluted capitals and an archivolt. It is accessed via a step laid with modern red tiles. Two round-headed window openings flank the door, detailed in the same style as the entrance, with three windows above. The symmetrical south elevation has three window openings at first floor, the rightmost of which is blank. The ground floor centre has a bow bay containing a Venetian-style window, flanked on each side by a full-height square-headed blank window opening.

The west, rear elevation is abutted to the left of centre by the two-storey return. It has a round-headed stairwell window to the centre, windows at first and ground floor to the right, and two covered openings at basement level whose details were not visible at the time of inspection. The return is four windows wide at first floor on its south elevation, with two windows at ground floor and a single-storey 20th-century flat-roofed extension to the left, noted as being of little interest. There is a six-panelled modern timber door to the right. The north elevation of the return has two windows at both first and ground floor, with a recessed left section containing a window at first floor that was not visible at inspection. The west gable has a window at first and ground floor to the right of centre. The north elevation is detailed in the same manner as the south.

The main domestic block was the first section of the building to be constructed. The two-storey western service wing was added later, most likely in 1827, as that date is inscribed on many of its wall plates. Local tradition holds that the house was built gradually over a number of years, originally designed solely for summer use without fireplaces or servants' quarters; chimneys and fireplaces were installed at an unknown later date when the house came to be occupied outside the summer months. An early painting of Seaport Lodge depicts rounded Gothick glazing to the ground floor, but the original glazing bars were replaced around the turn of the century when Colonel E. Douglas Leslie came into possession of the property.

The building was constructed as a summer seaside residence for the Leslie family of Glaslough. Historians Brett and Girvan give the construction date as around 1770, while the Ordnance Survey Memoirs of around 1835 suggest a slightly later date of around 1790. Brett records that the house was built by James Leslie soon after the completion of his main residence, Leslie Hill, in 1772, and suggests that erecting two major houses in such quick succession may have overstrained the family finances. By 1832, the first edition Ordnance Survey maps showed the house in its current layout. The Ordnance Survey Memoirs for that year recorded Portballintrae as consisting of only a few houses chiefly occupied by pilots, but noted that "near this to the west side of the bay is Seaport House, the summer residence of James Leslie Esquire," and that although its situation was "exposed and unprotected, [the location] was admirably calculated for that of a bathing lodge." The Townland Valuations of the 1830s initially valued James Leslie's residence at £45 7s. 5d., noting it was "too good for [a] bathing lodge and not likely to get a tenant if vacant," before reducing the valuation to £38 in a later revision.

No discernible alteration to the layout appeared on later Ordnance Survey editions from 1855 to 1921. By Griffith's Valuation of 1859 the value had been slightly revised upward to £40, and occupation had passed from James to Henry Leslie, who was recorded as both occupant and owner. Henry Leslie continued to reside at Seaport Lodge until his death in 1864, when the property passed to his widow, Harriet Ann Leslie. Annual Revision records continued to carry Henry Leslie's name until as late as 1882, when Colonel E. Douglas Leslie came into possession. Colonel Leslie resided there until 1908, when James G. Leslie took over. Despite changes in ownership, Seaport Lodge remained sporadically occupied as a summer residence and was vacant during both the 1901 and 1911 censuses, both conducted in April. James Leslie continued to be recorded as occupant until the end of the Annual Revisions in 1929, when the site value remained at £40. The property remained in Leslie family ownership until the mid-20th century, was listed in 1977, and has since remained in private ownership. At the time of the listing record, stabilising work was being carried out to the interior.

The house also possessed a number of outbuildings. The most significant of these, its coaching stables, still survive and have been converted into a public house and restaurant, forming part of what is now known as Beach Park. Seaport Lodge is prominently sited on a large plot on the western tip of the bay, visible from most parts of the village. The grounds are lawned on all sides, with a gravel forecourt to the front and a tarmacadamed yard to the rear. The northern boundary with the coastline is marked by a simple timber fence. The site is accessed from the southeast through a replacement timber gate supported on painted square gate piers with pointed caps. A gravelled laneway from the south, lined with modern two- and three-storey detached houses and apartment blocks, leads to the entrance. At the south entrance on Bayhead Road stands the former land steward's house and stables, now Beach Park.