Aca­dia Nation­al Park pro­tects the nat­ur­al beau­ty of the high­est rocky head­lands along the Atlantic coast­line of the Unit­ed States, an abun­dance of habi­tats, and a rich cul­tur­al her­itage. At 4 mil­lion vis­its a year, it’s one of the top 10 most-vis­it­ed nation­al parks in the Unit­ed States. Vis­i­tors enjoy 27 miles of his­toric motor roads, 158 miles of hik­ing trails, and 45 miles of car­riage roads. Size: 49,000 acres