An "an engineering marvel" is how experts describe the 2,120-foot-long Penobscot Narrows Bridge, which opened in 2006 and which is taller than the Statue of Liberty. It's certainly beautiful to look at—from the surrounding countryside it pops up on the horizon like the towers of a fairy-tale castle. Spanning the Penobscot River across from Bucksport, the bridge's 437-foot observation tower is the tallest in the world; an elevator shoots you to the top. Don't miss it—the panoramic views, which take in the hilly countryside and the river as it widens into Penobscot Bay, are breathtaking. In summer, the observatory often offers moonrise viewings.
Also here is Fort Knox, the largest historic fort in Maine. It was built between 1844 and 1869, when, despite a treaty with Britain settling boundary disputes, invasion was still a concern—after all, the British controlled this region during both the Revolutionary War and the War of 1812. The fort never saw any real action, but it was used for troop training and as a garrison during the Civil War and the Spanish-American War. Visitors are welcome to explore the many rooms and passageways. Guided tours are given daily during the summer and several days a week in the shoulder seasons.