There have been some fortifications in Lappeenranta city from the 17th century. After the defeat of Sweden-Finland in Great Northern War 1700-1721 Viborg castle and large areas in Carelia were lost to Russia. The military value of Lappeenranta, the new border city, was suddenly increased. The construction of the new bastion fortress was started immediatelly after war in 1721. It was planned to be a part of the new defence system of Finland together with Olavinlinna castle and Hamina fortress.
Russians conquered the fortress in the next war in 1741 after bloody battle. New border was moved to west and Lappeenranta was left to Russian side. Russians settled a garrison to fortress and started to enhance it in the 1750's and again in 1791-1792. After the Finnish War in 1808-1809 fortress lost its military value. After year 1810 it was used as a garrison and prison. During the Finnish Civil War in 1918 red guards were arrested and executed in Lappeenranta fortress.
Nowadays fortress has been renovated and open for visitors. The former garrison buildings are now home to the South Karelian Museum and Art Museum, artists' and craft workshops, Lappeenranta's Orthodox church and parish hall, a children's art school and a café, among others.
La Hougue Bie is a Neolithic ritual site which was in use around 3500 BC. Hougue is a Jèrriais/Norman language word meaning a \'mound\' and comes from the Old Norse word haugr. The site consists of 18.6m long passage chamber covered by a 12.2m high mound. The site was first excavated in 1925 by the Société Jersiaise. Fragments of twenty vase supports were found along with the scattered remains of at least eight individuals. Gravegoods, mostly pottery, were also present. At some time in the past, the site had evidently been entered and ransacked.
In Western Europe, it is one of the largest and best preserved passage graves and the most impressive and best preserved monument of Armorican Passage Grave group. Although they are termed \'passage graves\', they were ceremonial sites, whose function was more similar to churches or cathedrals, where burials were incidental.