4 Eldon Terrace

4 Eldon Terrace is a two-storey and attic, two-window building, likely dating from the 18th century, built in stucco with architectural details that harmonise with the other terraces in Upper Bangor. Numbers 1 to 4 are designed as reflected pairs. The roofs are slate, with boarded eaves and dentillation on number 3. The building has brick and rendered chimney stacks, and gabled dormers clad in slate. There is a mix of sash and casement windows, with splayed bay windows at numbers 3 and 4. Numbers 1, 3, and 5 feature stucco wreath motifs above an egg and dart cornice, along with end pilasters decorated with acanthus foliage. Most windows retain moulded architraves, bracketed cills, and stucco lintel ornaments. Each pair of houses has a doorcase featuring Ionic pilasters, a cornice, and brackets carved with foliage, a design also seen at number 5. The doorways are recessed, with half-glazed doors at numbers 1 and 2, and twin-arched-panelled doors at numbers 3 to 5.

The front is bordered by rubble walls supporting ornate cast iron railings with intersecting pointed arches, though these have been removed at number 5. A stucco ornament is situated above the door to the side passage.