Military-history fans will be in heaven at this fort, set right on Lake Champlain. Built by the French in the 1750s, the high-perched bastion protected the narrow strip of waterway connecting Lake George to the north. Since 1909 it's been open to the public, detailing the military history of the Lake Champlain and Lake George valleys. The collection is anything but dry: On view are nearly 1,000 muskets, bayonets, pistols, and swords from the 18th century, as well as a unique collection of uniforms. Not interested in the military stuff? Spend some time strolling through the gorgeous gardens surrounding the fort.