South Lodge, Lethen House

South Lodge at Lethen House is a gate lodge built in the later 19th century. It is a two-storey, asymmetrical building with a south-facing, three-bay L-plan frontage. The structure is made of coursed rubble with tooled ashlar dressings. The entrance is located near the center in a re-entrant and features a double leaf plank door with ornate cast-iron hinges. To the left, there is a projecting gabled wing with a tripartite window on the ground floor, while the east gable has a bipartite window on the ground floor. The lodge includes chamfered architraves, lattice pane glazing, and carved stone finials in the shapes of a rose, thistle, and shamrock at the apex. It also has a battery of three octagonal ridge stacks and a slate roof.