To the south - east of Horodło market, nearby the Bug River there is a settlement with the remains of the castle. By the locals it is called the Jagiellonian Ramparts. The archaeological findings prove the existence of the castle as early as 10th-13th century, so in the heyday of the famous Grody Czerwińskie. In the fourteenth century on the site of the old town there was a wooden castle built that was repeatedly destroyed and rebuilt at various periods of history. This is where the government signed the Act of Union in Horodło. Since 1462, the castle was the seat of the royal governors. The castle was finally destroyed in 1702 by the Swedes.