Eastern Ontario is a region of Southern Ontario approximately 35,296 km2 (13,628 sq mi) with an extended area of around 7,028 km2 (2,714 sq mi). The region is home to approximately 1,647,000 people2004 and comprises several census divisions ("counties"): Prescott and Russell, Stormont, Dundas and Glengarry, Leeds and Grenville, Ottawa, Lanark, Renfrew and Frontenac. The National Capital Region is an official federal designation for the Canadian capital of Ottawa, the neighbouring city of Gatineau, Quebec, and the surrounding area.
60% of Eastern Ontarians live in the City of Ottawa. Other major cities (40,000+) in the region include Kingston and Cornwall. Major towns under 40,000 people include Pembroke, Rockland, Hawkesbury, Smiths Falls, Carleton Place, Renfrew, Arnprior, Embrun and Perth.
The Thousand Islands is the name of an archipelago of islands that straddle the Canada-U.S. border in the Saint Lawrence River as it emerges from the northeast corner of Lake Ontario. They stretch for about 50 miles (80 km) downstream (Northeast) from Kingston. The Laurentian Highlands, which form a small section of the extensive Canadian Shield, cuts through the western section from the Upper Ottawa River valley southeast toward to the Saint Lawrence River around Gananoque. The eastern section of Eastern Ontario, that is east and south-east of Ottawa, is generally a flat plain. Along the extreme western edge of Eastern Ontario are a continuation of the Laurentian Highlands, known as the Opeongo Hills, and they contain some of the highest elevations in Southern Ontario. They stretch into the northern portions of Central Ontario, near Algonquin Provincial Park. Ottawa itself is at the confluence of the Rideau River and Ottawa River.