Iceland!

I've been to Victoria, Iguazu and Niagra Falls as well as many smaller, but still impressive falls around the world. However, for a single viewpoint, I don't think any of them beat Guilfoss Falls. It's hard to put into words the allure and photos can't fully capture the magnificence of this falls. Something about the way that the water cascades down multiple channels one direction before pouring over the side perpendicularly on the next level down and then returning to the original direction make this falls seem almost like an optical illusion. It's also that perfect compromise between impressive scale and yet not as fierce as Iguazu or Victoria such that the very volume of the falls obscures the view itself. 

Gullfoss is an easy 90 minute drive from Reykjavik along paved highway. Unlike similar sites in the US, there's no admission fee and even the parking is fee. Best of all, the route to the falls takes you past the also impressive Geysir thermal area and the Kerid Crater. 

The Kerid Crater has free parking and a small admission fee ($3), but rewards with lovely views of the turquoise water filled crater. You can walk around an upper loop for views down to the crater or a lower loop at water level. Either one only takes about 15-20 minutes. 

Geysir, the namesake of the term 'geyser' is now dormant, but there's another reliable Geysir a few hundred feet away, Stokkur, that erupts about every 10 minutes. Parking and the site are also free and you can wonder amongst the bubbling pools and admire the smaller thermal features while you wait for Strokkur's next eruption. Unlike Yellowstone's Old Faithful, the entire complex feels much less chaotic and over commercialized.

Together with other smaller sites, these features make up the 'Golden Circle' route outside of Reykjavik, a nice day tour that can be completed independently via rental car or as a part of several day tour options if you don't feel up to driving the sometimes narrow, winding highways of Iceland.