Zavikon Island refers to either the larger or the pair of islands in the Thousand Islands

Thousand Islands

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 downstream from Kingston, Ontario. The Canadian islands are in the province of Ontario, the...

 archipelago on the St. Lawrence River between New York

New York

New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

 and Ontario

Ontario

Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....

, two kilometres southeast of Rockport, Ontario and about 200 meters north of the international boundary. As confirmed by various USGS and US Department of Defense maps, Zavikon Island is located in Canadian territory and belongs to the Leeds and Grenville

Leeds and Grenville United Counties, Ontario

The United Counties of Leeds and Grenville are located Ontario, Canada. The population, as of the 2006 census, was 99,206. The United Counties have a land area of . Leeds and Grenville are located in the subregion of Southern Ontario named Eastern Ontario, and front on the St. Lawrence River and...

 municipal unit.
The smaller and more southeasterly of the pair of islands is sometimes called Little Zavikon Island. It has a US-Canada Boundary Commission

Canada-United States border

The Canada–United States border, officially known as the International Boundary, is the longest border in the world. The terrestrial boundary is 8,891 kilometers long, including 2,475 kilometres shared with Alaska...

 reference monument, from which, along with other reference monuments on the shore and islands, surveying measurement are used to calculate the international boundary line turning points in the waterway (in this case, about 140 meters southsoutheast of the southern tip of Little Zavikon Island as shown on the largest scale USGS map of the area.

A popular but incorrect tale among local guides is that the larger island is in Canada, while "Little Zavikon Island" is in the United States, and the footbridge between them is the "shortest international bridge in the world"

In 1985, the islands hosted the first Zavikon Conference organized by the Dräger Foundation.