The Bárðarbunga volcano in central Iceland is currently erupting, and looks amazing.
What options exist to visit the volcano?
Sightseeing flights are available (e.g. Mýflug) and cost around 300 euros per person.
However, there is currently no way for tourists to approach the eruption on land due to the extremely hazardous conditions on the ground.
[...] due to the volcanic eruption in the area north of Vatnajökull glacier, the highland north of Vatnajökull glacier is closed for all traffic.
-- From the latest (15.09.2014) status report from the Civil protection agency in Iceland
Edit: I should add that it seems that the eruption is waning. No telling how it will develop, of course. This might be the end, or merely the end of the beginning.