Visiting dams is also pretty high on the list.
Now, tourists can combine the best of both worlds and travel to China to visit the largest dam in the world.
Three Gorges Dam is not fully functioning yet, but the 610 foot tall structure is certainly something to behold. No other structure on this planet, for example, is made out of more concrete than this Chinese monstrosity. And the reservoir it has created will eventually stretch for an incredible 400 miles.
Local officials are anticipating that a million tourists a year will come to pay homage to this hydroelectric beast. At a $25 billion price tag, Three Gorges Dam just might be the most expensive tourist dive ever built.