See Alaska’s wilderness from a zip line starting May 6. The four-hour Mammoth Waterfalls and Ultra Zip-line Adventure, run by Alaska Excursions, includes a 30-minute narrated drive from Skagway’s cruise ship dock to the town of Dyea. After a safety briefing and orientation, you can soar among the treetops on 11 zip lines that are up to 750 feet long, and also traverse four sky bridges that overlook waterfalls and the forest floor, about 30 feet below. Riders must weigh between 65 and 265 pounds. Rates: $159 adults, $139 children up to age 12.