Just over 100 km east of Icelandic capital, Reykjavík, Strokkur ("Churn") serves as the crown jewel of the Haukadalur geothermal area and one of the most popular natural attractions in the country. Part of this is its accessibility and the fact that it is joined by a number of other geysers, mud pools, and fumaroles, but you can't deny the heady appeal of a fountain that spurts up to 40 meters into the sky (although it has also been known to just grumble indignantly on some unfortunate occasions).
Erupting every 4-8 minutes, Strokkur is a mainstay of the Golden Circle route and can often be self-driven and enjoyed without the need of a tour guide. It'll be chilly and windy for the most part after October, so be sure to dress as warmly as possible if your Icelandic adventure is planned for the off-season.
Location:Haukadalur geothermal area
Note:Be sure to also check out Geysir, Strokkur's sister geyser, which erupts far more infrequently, but with much more gusto when it does (70 recorded meters in the past).