Charlestown harbour was purpose built in 1801 by Charles Rashleigh (after whom it as named) for the export of china clay, copper and tin. Charlestown was a coal importing port. It was designed by John Smeaton, the man responsible for the Eddystone Lighthouse. In 1790 the settlement was known as West Polmear and had a population of 9 people, this had swelled to 3184 by 1911 in its heyday

There is a Charlestown Shipwreck Museum, which also shows the life of the port in Victorian times. The many and varied exhibitions reflect village life in Charlestown, it's history, shipwrecks and the once thriving China Clay industry. As well as artifacts from 150 odd shipwrecks, the museum records maritime history dating back to 1715. It also has one of the largest underwater diving equipment collections in the country, including diving suits used for treasure seeking and naval purposes.

Charlestown harbour and two beaches on either side of the harbour entrance are owned by Square Sail, a company who own and operate a fleet of tall ships, one or two of which can often be found at anchor in the harbour, and are sometimes open for tours. The best-known tall ship to regularly visit the port was the Maria Asumpta, launched in 1858 and was the world's oldest working square-rigger. The Maria Asumpta ran aground May 1995 and broke up on the north Cornish coast, with the loss of three of her sixteen crew.

Charlestown harbour has several times been transformed into historic ports like Bristol for film and television productions. For example, it has starred in an adaptation of Jane Austen's "Persuasion" and films such as "The Three Musketeers" (1993 version), The Voyage of Charles Darwin", the "Onedin Line" and "Poldark" have all had some scenes shot here.

During the 19th century the ancillary businesses for the port developed such as boatbuilding, ropemaking, brickworks, lime burning, net houses, bark houses and pilchard curing.

The harbour continues today as a working port and a small amount of china clay is still exported, which has stopped it becoming a "tourist village". It has has largely escaped 'development' and so has retained its original character.The harbour also is the home port for a number of "tall ships" which are used in film productions all over the world.

Charlestown has its own beach, with safe bathing at Porthpean Beach