Of course, there's the volcano: Haleakala's summit stands more than 10,000 feet above sea level (in fact, you can see three different islands from its peak on a clear day). For a once-in-lifetime ...

If you have extra time, Virgin Islands National Park (St. John ... alike have their choice of 20 trails to hike. Water-based activities include snorkeling, boating and fishing (permits are ...