Fodor's Expert Review Portland Observatory
This octagonal observatory on Munjoy Hill was built in 1807 by Captain Lemuel Moody, a retired sea captain, as a maritime signal tower. Moody used a telescope to identify incoming ships, and flags to signal to merchants where to unload their cargo. Held in place by 122 tons of ballast, it's the last remaining historic maritime signal station in the country. The guided tour leads all the way to the dome, where you can step out on the deck and take in views of Portland, the islands, and inland towards the White Mountains.