Wailua Falls on the island of Kauai, Hawaii:
These waterfalls are easily captured from a roadside stop — but that’s both good and bad.  Good if time’s short, but bad because you’ve got just one perspective you can take on the subject.  There are… informal… trails that lead down toward the level of the pool at the bottom of the falls.  But so many people have died falling from them, that they’ve been closed off for years.  Officially, at any rate.