The spa for the citizens of Gdańsk has been active since the 16th century. Until the end of that century most noble and magnate families from Gdańsk built their manor houses in Sopot. During the negotiations of the Treaty of Oliva King John II Casimir of Poland and his wife Queen Marie Louise Gonzaga lived in one of them, while Swedish negotiator Magnus de la Gardie resided in another — it has been known as the "Swedish Manor" ("Dwór Szwedzki") ever since. The Swedish Manor was later the place of stay of Polish Kings Augustus II the Strong (in 1710) and Stanisław Leszczyński (in 1733).