An "an engineering marvel" is how experts describe the 2,120-foot-long Penobscot Narrows Bridge, which opened in 2006. 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 highest 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.
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 feared—the Brits controlled this region during the Revolutionary War and again during the War of 1812. The fort never saw any actual fighting, 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 passageways and many rooms. Guided tours are given daily during the summer and several days a week in the shoulder seasons.