There is an island in the Niagara River about 5 kilometres (3 miles) above Niagara Falls called Navy Island. This uninhabited Canadian island is a nature reserve. It received its name during the 1760s when a British shipyard was located here. This is where a number of ships were built for the Royal Navy to be used in the upper Great Lakes.
At one time Navy Island was suggested as the site of the United Nations headquarters (it eventually was located in New York City).
Today, you can obtain a permit from the Niagara Parks Police for day visits and overnight camping. Of course you have to have a boat to get there.
I’ve attached a sepia sketch of Navy Island drawn in 1842 by William Henry Bartlett as seen from the Canadian side of the boarder. Remember, this is a very old print.