Thunder Hole

Even on a perfectly clear day, Thunder Hole will sound like a storm barreling down the coast. The noise making the inlet famous is created when an arriving wave forces air and water out of an underground cavern. The effect is produced only under specific conditions. Nevertheless, visit Thunder Hole any time for a short hike with stunning views of the Maine coast and sounds of waves crashing against the rocks.

Head to Thunder Hole about 3 hours before high tide, when waves start to roll in and the famous phenomenon becomes more likely to occur. Park in the on-site lot or take the shuttle bus to avoid crowds. When roses are in season, sniff their bushes of exuberant blooms in magnificent color next to the trailhead.

Admire the inlet from above, where it is possible to see the water rolling in and the white foam at the crests of the waves, then head down the well-maintained steps. A railing offers helpful support, especially during wet conditions.

Listen for the sound of the thunder at the base or sit on a rock and gaze out to sea. Look for Otter Cliff, whose 110-foot (36-meter) cliff makes it one of the tallest headlands in the Western Hemisphere.

See Thunder Hole on foot from the Ocean Path, which leaves from Sand Beach and goes to Otter Cliff 2 miles (3 kilometers) to the south.

Thunder Hole is located on the southeastern edge of Mount Desert Island, down the coast from Bar Harbor. Drive from Bar Harbor in about 13 minutes or from Southwest Harbor in 30 minutes. Bangor, which has the closest commercial airport, is about 1.5 hours away. Parking is available in an on-site lot, which can get full at peak viewing hours. Park instead in Bar Harbor or elsewhere on the island and take the free Island Explorer bus, which passes Thunder Hole every 30 minutes.

There is a fee to access Acadia National Park. Use extreme caution when visiting Thunder Hole, especially when a storm is imminent, as surges can be unpredictable. Check the weather forecast before visiting.