A tidal harbour on the rocky East Lothian coast, Port Seton Harbour is B-listed. The earliest recorded harbour here dates from 1655, built by the Setons, and once functioned as the port for Prestonpans, exporting salt and coal. Having suffered from poor maintenance, it was rendered unusable by a storm in 1810, and it was not until 1880 that a new harbour was built here by the engineering brothers David and Thomas Stevenson at a cost of £12,000. This was funded by local fishermen with help from the Earl of Wemyss and March, who by that time owned the land. This is an early example of mass-concrete construction making use of a basement of natural rock. The basin was divided, creating the inner harbour, with the building of the Middle Pier in 1885 at a cost of another £5000.
Today, the harbour is a trust port, run by the Port Seton Harbour Commissioners. It hosts leisure craft and a few fishing boats.