This four-story artillery fort was constructed under Henry VIII’s rule between 1540-1542. It is situated in a prime position overlooking the Carrick Roads, the name given to the wide estuary of the River Fal.

This is one of the widest natural harbors in the world, making it a prime spot for the passage of ships going to and from the Mediterranean Sea and the Atlantic Ocean. The anchorage of many ships in this area made it a vulnerable area for potential attack and invasion from Europe. St. Mawes Castle and the nearby Pendennis Castle were both built in the mid-16th Century to strengthen the coastal defense against this threat. 

The castle was built with a central four-story tower and had three rounded bastions on each side which were used as platforms for the 19 artillery pieces alongside many smaller guns. Inside the castle, there are extensive carvings and inscriptions in the stonework which pay tribute to Henry VIII and other leading royalty at the time. Many of these Latin inscriptions and carved sculptures still exist and can be seen to this day. 

St. Mawes Castle remains one of the best-preserved forts of its time and those who visit gain a fascinating insight into what life was like in that time. One particularly interesting part of the castle is the underground  “oubliette,” where prisoners or soldiers would be punished by being locked away for a period of time. The kitchen, storeroom, and gunpowder store can also be seen. Visitors can climb up the stairs to the top of the castle keep, giving great views out to the sea (and to keep an eye out for any potential invaders!).