The St. John's Church in the Hamina city centre was built in 1841-1843. It was designed by famous architect Carl Ludvig Engel and represents the Neoclassicism style with strong influence of Greece temples.
Before the present church there was a church of Ulrika Eleanora (built in 1732, destroyed by fire in 1742) and the commandant’s house. The residence of the fortress commander was the place where the Russian negotiators lived and signed the Treaty of Hamina (after the Finnish War in 1809).
Château de Falaise is best known as a castle, where William the Conqueror, the son of Duke Robert of Normandy, was born in about 1028. William went on to conquer England and become king and possession of the castle descended through his heirs until the 13th century when it was captured by King Philip II of France. Possession of the castle changed hands several times during the Hundred Years' War. The castle was deserted during the 17th century. Since 1840 it has been protected as a monument historique.
The castle (12th–13th century), which overlooks the town from a high crag, was formerly the seat of the Dukes of Normandy. The construction was started on the site of an earlier castle in 1123 by Henry I of England, with the 'large keep' (grand donjon). Later was added the 'small keep' (petit donjon). The tower built in the first quarter of the 12th century contained a hall, chapel, and a room for the lord, but no small rooms for a complicated household arrangement; in this way, it was similar to towers at Corfe, Norwich, and Portchester, all in England. In 1202 Arthur I, Duke of Brittany was King John of England's nephew, was imprisoned in Falaise castle's keep. According to contemporaneous chronicler Ralph of Coggeshall, John ordered two of his servants to mutilate the duke. Hugh de Burgh was in charge of guarding Arthur and refused to let him be mutilated, but to demoralise Arthur's supporters was to announce his death. The circumstances of Arthur's death are unclear, though he probably died in 1203.
In about 1207, after having conquered Normandy, Philip II Augustus ordered the building of a new cylindrical keep. It was later named the Talbot Tower (Tour Talbot) after the English commander responsible for its repair during the Hundred Years' War. It is a tall round tower, similar design to the towers built at Gisors and the medieval Louvre.Possession of the castle changed hands several times during the Hundred Years' War. The castle was deserted during the 17th century. Since 1840, Château de Falaise has been recognised as a monument historique by the French Ministry of Culture.
A programme of restoration was carried out between 1870 and 1874. The castle suffered due to bombardment during the Second World War in the battle for the Falaise pocket in 1944, but the three keeps were unscathed.