Geysir

Going to Iceland this summer, the thing I wanted to see the most was the famed Geysir on the Golden Circle Route. 

If you just sneered at the unoriginal name, think again - Geysir was in fact the first to be known to Europeans and is the namesake for all other geysers on the planet. Now that's some bragging right!

As impressive as it was seeing the geyser spout twenty metres high, I thought the coolest part was the five seconds right before it:

First the pool of water starts to slosh from side to side, as if a silent gust of wind was ripping across its surface. Getting increasingly violent, it suddenly expands up-and-outwards in a burgeoning turquoise bubble, with a living swell of white froth in its center that bursts through and explodes into a tower of boiling water -- almost like the breath of air you release in a rush after holding it right to your limit.