Fort Holmes is a fortified earthen redoubt located on the highest point of Mackinac Island. Originally built in 1814 by British forces during the War of 1812, the redoubt was improved by that army throughout the course of the war to help defend the adjacent Fort Mackinac from a possible attack by the U.S. Army.
The British named the redoubt Fort George and reinforced it with cannon, a blockhouse, and a magazine for gunpowder and other munitions. However, Fort Holmes never functioned as an independent military fortification. It was always a dependent outpost of nearby Fort Mackinac.
Wikipedia https://en.wikipedia.org/wiki/Fort_Holmes
Address Fort Holmes Rd, 49757, United States
Coordinates 45°51'29.278" N -84°36'58.938" E