Hiking is the most rewarding shore excursion available from a cruise ship, and it is consistently underbooked. Most cruise passengers default to bus tours and beach days, which means the trails above the ports are often uncrowded even when the waterfront is packed.

The range of hiking available from cruise ports is extraordinary. In Alaska, you can walk through old-growth temperate rainforest or scramble to a summit above the Inside Passage. In the Caribbean, you can climb active volcanoes or hike through cloud forest to waterfalls. In the Mediterranean, you can walk ancient paths along coastal cliffs with views that have not changed in centuries.

Here is where to find the best hiking at major cruise destinations.

Alaska's Inside Passage ports offer some of the most accessible wilderness hiking in North America. The trails are well-maintained, the scenery is extraordinary, and the wildlife -- bears, eagles, deer, and occasionally wolves -- is a genuine possibility.

Juneau: The Mount Roberts Trail gains 3,500 feet from the downtown waterfront to a summit with views over the Gastineau Channel and the surrounding peaks. The lower sections are accessible by the Mount Roberts Tramway if you want to skip the climb. The East Glacier Trail at Mendenhall Glacier offers a more moderate option with views of the glacier face.

Ketchikan: The Perseverance Trail climbs steeply through old-growth forest above the city. The Ward Lake Recreation Area has easier trails through the Tongass National Forest. Both offer the temperate rainforest experience -- Sitka spruce, western hemlock, moss-covered forest floor -- that defines Southeast Alaska.

Skagway: AB Mountain (Skagway Mountain) rises directly behind town and offers one of the most rewarding summit hikes accessible from any cruise port. The trail gains 3,500 feet in 3.5 miles and delivers views over the Lynn Canal and the White Pass. The Dewey Lakes Trail system offers easier options for those who want forest hiking without significant elevation gain.

Sitka: The Indian River Trail follows a salmon stream through old-growth forest to a waterfall. The trail is flat, well-maintained, and appropriate for all fitness levels. The Gavan Hill Trail climbs more steeply and offers views over Sitka Sound and Mount Edgecumbe.

The Caribbean islands offer dramatically different hiking from Alaska -- tropical vegetation, volcanic terrain, and views over turquoise water.

St. Lucia: The Gros Piton hike is one of the great Caribbean hiking experiences. The trail climbs 2,619 feet in about 2.5 miles to the summit of one of the island's iconic volcanic plugs. The views from the top -- the Caribbean Sea, the Pitons, and the island's interior -- are extraordinary. The hike requires a guide (mandatory by law) and takes three to four hours round trip.

Dominica: The Boiling Lake hike is the most challenging day hike in the Caribbean. The trail crosses the Valley of Desolation -- a volcanic landscape of fumaroles, hot springs, and sulfur vents -- before reaching the second-largest boiling lake in the world. The hike takes six to seven hours round trip and requires a guide. It is strenuous and not appropriate for casual hikers, but it is unlike anything else in the region.

St. Kitts: Mount Liamuiga, a dormant volcano, rises 3,792 feet above the island. The trail to the crater rim takes three to four hours and passes through rainforest, cloud forest, and elfin woodland. The crater contains a lake and the views from the rim extend to neighboring islands.

Martinique: The Montagne Pelée hike climbs to the summit of the volcano that destroyed the city of Saint-Pierre in 1902, killing 30,000 people. The trail passes through cloud forest and volcanic rock to a summit with views over the island and the Caribbean.

The Mediterranean offers hiking through landscapes that have been walked for thousands of years -- ancient paths, coastal cliffs, and mountain villages.

Santorini, Greece: The caldera walk from Fira to Oia is one of the most scenic hikes in Europe. The trail follows the rim of the volcanic caldera for about 10 kilometers, with views over the caldera, the Aegean, and the whitewashed villages below. Allow three to four hours.

Cinque Terre, Italy: The Sentiero Azzurro (Blue Trail) connects the five villages of Cinque Terre along the Ligurian coast. The full trail is about 12 kilometers and takes five to six hours. Individual sections can be walked in shorter time. The trail passes through vineyards, olive groves, and along cliff faces above the sea.

Dubrovnik, Croatia: The Srđ Mountain trail climbs from the old city to a summit with views over Dubrovnik, the Adriatic, and the Elafiti Islands. The trail takes about 45 minutes each way and is steep but manageable. The cable car is an alternative for those who prefer not to hike up.

Kotor, Montenegro: The Ladder of Kotor is a medieval path that climbs from the old city to the fortress above. The path gains 1,200 feet in about 1.5 kilometers and passes through the old city walls. The views from the fortress over the Bay of Kotor are among the best in the Adriatic.

Fitness level: Be honest about your fitness level when choosing a hike. A strenuous hike that exceeds your abilities will be miserable; a moderate hike that matches your fitness will be memorable.

Time: Most hiking excursions run three to five hours. Factor in travel time to the trailhead and back to the ship. Build in a buffer before all-aboard time.

Guided vs. independent: Some trails require guides (Gros Piton, Boiling Lake). Others are well-marked and easy to navigate independently. For unfamiliar terrain, a guide adds safety and context.

Footwear: Wear proper hiking shoes or trail runners. Sandals and flip-flops are inappropriate for most hiking excursions. Waterproof footwear is essential in Alaska.

What to bring: Water (at least one liter per person), snacks, sunscreen, a hat, and a light rain jacket. In Alaska, add insect repellent and waterproof layers.

Book in advance: Popular hiking excursions sell out early, especially in Alaska during peak season.

Independent hiking: Many of the best hikes are accessible independently without booking a tour. Research the trailhead location and transportation options before your port call.

Weather: Hiking excursions are weather-dependent. Have a backup plan for rain or extreme heat.

The trails above cruise ports are among the best-kept secrets in travel. While most passengers are on the waterfront, the mountains above are quiet, the views are extraordinary, and the experience is genuinely different from anything you can get from a ship deck. Lace up your boots and go find them.