When it was established in 1919, Acadia (then known as Lafayette National Park) became the first national park east of the Mississippi River. Though it's spread across over a dozen islands along the coast of Maine, the heart of the park lies on Mount Desert Island – named for the barren, rocky summits of its highest mountains.

This is the highest summit on eastern seaboard of the United States, looming 1,528 feet above Bar Harbor and Frenchman Bay. A network of trails provides access to and around the rocky summit with its expansive views, though there's a road to the top, too. Reservations are required for this popular drive, so be sure to plan ahead if you're trying to see Acadia's most-popular sight: sunrise from the top of Cadillac Mountain.

Situated east of Bar Harbor, this is the only portion of Acadia that lies on the mainland. A loop road winds along the coast here, dipping in and out of coves and forest and accessing a spur to the southernmost point on the peninsula: Schoodic Point. Gulls congregate on the granite outcrops that line the shores while eiders and scoters bob in the surf off the coast.

Jordan Pond fills a basin carved by long-gone glaciers, ringed with the rounded summits of mountains that were also sculpted by these rivers of ice. A hiking trail circumnavigates the lake, but there are opportunities for recreation out on the water, too. Canoeing and kayaking are popular pursuits here, but the lake is closed to swimming, paddleboarding, and oarboarding.

When the tides recede in Bar Harbor, the sand bar that gives the area its name is exposed above the water, forming an ephemeral land bridge from the mainland to Bar Island. It's a 2-mile round-trip hike from the mainland to the top of the island and back, but visitors must stay aware of the tides. The land bridge is exposed for roughly 90 minutes at each low tide. Staying on the island too long could mean waiting nine hours for the waters to recede again.

Filling a basin on the western side of Mount Desert Island, Echo Lake can provide a quieter alternative to the ever-popular Jordan Pond. Swimming is permitted here, along with paddling these glassy waters that reflect the trees and mountains above. A short but challenging hike ascends to Beech Cliff above the lake's southwestern end, offering sweeping views of the area.

A narrow cleft in the rocks funnels the full force of incoming waves into this confined space, resulting in a thundering burst of escaping air and pushing sprays of seawater high above the coastline. The best times for witnessing this display of ocean power are genearlly one to two hours ahead of high tide.

Appropriately named, this is the largest sand beach in the park and thus receives a healthy stream of visitors all summer long. Hiking trails head south along Newport Cove or out to the cliffs of Great Head.

These distictive, rounded twin summits rise on the north end of Jordan Pond, carved and smoothed by the action of the same glacier that gouged out the basin that the lake now fills. A 1.5 mile hike leaves from the Bubbles Divide Trailhead and yo-yos up the north summit and then back down to the south, though connections with other trails offer longer hikes for those so inclined. The rocky cliff faces on the flanks of the Bubbles are popular spots for rock climbing.