The bridge at Lugg crosses a small stream that eventually feeds into the Camac river west of Clondalkin, and it has seen no regular traffic since 1820, according to Healy's 1974 survey. What remains is essentially a skeleton: enough to read the original structure clearly, but stripped back by time to its bare bones.

The bridge dates to the 17th century, as recorded by O'Keefe and Simington, and it once carried the old coach road linking Saggart to Brittas, a route that served travellers crossing this part of south County Dublin before the road network was reorganised in the early nineteenth century. The construction is straightforward vernacular stonework: undressed mortared stone, meaning the blocks were used largely as quarried rather than carefully shaped, with keystones, the wedge-shaped stones that lock an arch in place, only roughly trimmed. The piers feature triangular cutwaters on their upstream faces, a practical design detail intended to split the current and reduce pressure on the structure during high water. Today the stream passes through the westernmost arch, suggesting either a shift in the watercourse or, more likely, that this arch was always the principal channel crossing.

The site is accessible on foot and rewards a close look at the masonry rather than any grand panorama. Without parapets, the bridge reads almost like a diagram of itself, the four arches and their piers clearly legible from the bankside. Visiting in late autumn or winter, when vegetation has died back, makes it considerably easier to examine the structure and appreciate the cutwaters properly. The surrounding area is quiet agricultural and peri-urban ground on the western fringes of Dublin, and the bridge sits without fanfare or signage, which is part of what makes finding it feel genuinely worthwhile.