Located on the eastern shore of Loch Fyne near Newton, Castle Lachlan was originally constructed in the 13th century but the tower or keep that stands today dates from the 15th. Its design was unique in Scotland, with the large keep containing two large tenements connected along the north side with a shared open court.The castle had four stories plus cellars and battlements and was protected by fortifications. A Great Hall on second floor was used as a council room and gathering hall on special occasions. Rain water was collected in a well for communal use. The MacLachlans were forced to flee the castle in aftermath of the Jacobite Rebellion. It was bombarded from the sea in 1746, after the Battle of Culloden, on the orders of Duke of Cumberland. Their lands were eventually restored to them with the assistance of their government allies which enabled Donald MacLachlan to commission the construction of the new MacLachlan or Lachlan Castle and its grounds.