The Eye of Quebec

Really Cool lake up in Canada. Found it by accident while looking on Google maps. A combination of Universe-made and Man made,
From Wiki:

"an annular lake in northern Quebec, Canada, the remnant of an impact crater (astrobleme) made approximately 212 million years ago, towards the end of the Triassic period. It is the 4th largest impact crater on earth. The island in the centre of the lake is known as René-Levasseur Island. Mount Babel is the central peak of the crater.

The crater was created by the impact of a 3 mile wide asteroid which excavated a crater originally about 62 mi wide although sediments and erosion have since reduced its diameter to about 45 mi.

The Manicouagan reservoir and René-Levasseur Island
are sometimes called the "eye of Quebec."

The lake was enlarged by flooding from the massive Manicouagan or Manic (Manic 1, Manic 2...) series of hydroelectric projects undertaken by Hydro-Québec, the provincial electrical utility, during the 1960s. The complex of dams is also called the Manic-Outardes project because the rivers involved are the Manicouagan and the Outardes. The lake covers an area of 20,990 square feet. Its eastern shore is accessible via Quebec route 389.

The Manicouagan lake acts as a giant hydraulic battery for Hydro-Québec. In the peak period of the winter cold, the lake surface is usually lower since the turbines are run all the time at peak load to meet the massive electrical heating needs of the province. The surface of the lake also sees record low levels in the extreme periods of heat in New England during the summer, since in that period Hydro-Québec sells electrical energy to the joint New England grid and individual utilities in the United States."

Google maps link Wikipedia page