Thousand Islands – Frontenac Arch is one of four ecoregions of the Mixedwood Plains. The Thousand Islands in the Saint Lawrence River have a distinctive flora and fauna and are a part of the biological corridor. The bedrock is mostly gneiss, granite and marble, more than a billion years old. The Frontenac terrain is the youngest of the Ontario portions of the arch, dated at 1.2 billion years old. These rocks were once part of a large mountain chain of the ancient supercontinent of Rodinia. There is also a meteor crater near Holleford, where the shield meets the limestone plains of southeastern Ontario. The area
Leeds and the Thousand Islands Island, Halsteads Bay, Holland, Ivy Lea, Junetown, La Rue Mills, Lansdowne, Leeds, Legge, Long Point, Lyndhurst, Maple Grove, Mitchellville, Narrows, Oak Leaf, Outlet, Pooles Resort, Quabbin, Rockfield, Rockport, Sand Bay Corner, Seeley's Bay, Selton, Soperton, Sweets Corners, Taylor, Tilley, Union, Warburton, Washburns Corners, Waterton, Willowbank and Wilstead. Lansdowne, Ontario is a small town located just north of Ivy Lea, Ontario and 4 km north of Highway 401, at the intersection of Leeds and Grenville County Roads 3 and 34. It is a part of the township of Leeds and the Thousand Islands, Ontario. It can be accessed by former Kings