The Harbour Walls and Bollards

The Harbour Walls and Bollards are located at St Michael's Mount in Marazion. Originally constructed around the early 15th century for William Moreton, archpriest of the Mount, the structure was remodeled around 1727 for Sir John St Aubyn, the third baronet, and largely rebuilt in 1824 for Sir John St Aubyn, the fifth baronet. The walls are made of granite rubble with dressed granite cast-iron bollards, some of which are reused cannons.

The harbour features an irregular enclosure walled on four sides. The south side serves as a retaining wall against the north shore of the island, while the north wall includes a large harbour entrance. The east wall connects to the causeway leading to the mainland, and the west wall has a raised walk behind the parapets. Inside the harbour, there are steps on either side of the entrances, with two flights of steps leading up to a projecting quay on the south side and three slipways at the south-east and south-west corners. Bollards are arranged slightly irregularly along the quays, and there are parapets on the seaward side of the three projecting walls. The harbour walls are slightly battered, with the lower parts made of large, roughly-hewn, irregularly coursed blocks that may date to the 18th century or earlier. Above this, there are vertically set stones likely from the 18th century, while the upper parts of the walls, steps, coping stones, and paved surfaces are mostly from the 19th century.