Gullfoss may be Iceland's most popular waterfall, and we can certainly testify to that statement as we saw it was always busy here.
This spectacular two-tiered waterfall (with each tier dropping at right angles to each other) drops a total of 32m while spanning the entire width of the Hvítá River. The upper tier drops about 11m while the lower tier drops 21m. Mist wafts up from the lower tier due to the quantity of falling water. It's one of the three major attractions on the Golden Circle Tour and Route, which we found very doable as a day trip out of Reykjavík.
It's hard to believe that this waterfall almost disappeared due to the desire for hydroelectricity by various interests. In some fortuitous bit of misfortune (if you're the investor) and lack of funds, attempts were unsuccessful and the falls was eventually sold to the state of Iceland. Despite further interest to utilize the river by the state, it was eventually conserved.
A more romantic story depicted Sigríður Tómasdottir (the daughter of the landowner who was about to sell his land, including the falls) threatened to throw herself into the falls if the land was sold. As a result, the father pulled out of the deal and the falls was made a reserve and the rest was history. It's said that this isn't true, but nonetheless we saw there was a memorial at the falls commemorating Sigríður Tómasdottir.
In addition to the hordes of tourists who are both self driving and on various tours, we also shared this waterfall with hordes of midges, which seems to be abundant in the early summer.
We took a short boardwalk and trail that provided frontal views from a car park area (not the main car park) as well as along a path that took us right to the brink of both sections of Gullfoss. There was also an upper viewing deck where we got the photo you see at the top of this page.
Directions: From Reykjavik, drive about 54km east along the Ring Road to the turnoff with route 35. Follow route 35 for over another 70km or so to the waterfall, passing by Geysir (another Golden Circle main attraction) along the way. There are actually two car parks for the falls (a lower one off route 334 and a much larger upper one next to a visitor centre off route 35). Although it's a little bit of a longer walk from the larger car park to get close to the falls, I personally don't think it matters much where you park unless you're elderly or disabled in which case the lower car park would be the desired option.
Julie at the end of the trail being dwarfed by the falls
View of Gullfoss from the lower overlook
Walkway leading closer to the falls
Looking down into the turbulent ravine below the bottom tier
Some lady checking out the wafting mist from the lower waterfall
Looking towards the left side of the Upper Waterfall
Unusual view of the falls; admittedly I had to hop the barricade to get this shot
Geysir - if you come out to see the falls, you mind as well make a stop here and check out the geysers. You should be able to see Strokkur (the frequently erupting one), but who knows? You might get lucky and see the great Geysir go off!