It is one of the finest Renaissance monuments in Ukraine. This house was built in 1580 by architect Peter of Barbone for Greek merchant Constantine Kornyakt one of Lviv's richest and most educated men. Three years later, in 1588, next to Italian Plato construction of Black Stone House started, famous for its stones, grown dark with age. After 1647 the House was the property of John Sobiesky, who in 1674 became the King of Poland. Eternal Peace Treaty between Poland and Russia was signed in this house in 1686, under which Poland gave up its claims to the left-bank Ukraine. Nowadays Lviv's conservatory arrange concerts and performances there every year, which became a good tradition.