Geothermal hot springs can be found all over the world, but these are some which hold most of the Travel Nugget's interest. Although some are lethal, the colours are surreal. THE BLUE LAGOON This shade of blue is so pretty, I can't believe that it's the natural colour of this hot spring. Yes, blue is my favourite colour. The Blue Lagoon is Iceland's most popular feature and I just want to jump into it. Its spectacular shade of blue water comes from a composition of silica, algae and minerals which reflects in the sunlight. The blue lagoon drink was actually named after here. However, the water itself is actually milky white. The lagoon contains 9 million litres of water, renewing itself every 40 hours from beneath the floor. The deepest area in the spring is 1.6 meters with a temperature of 37 to 40 degrees Celsius; both perfect for Travel Nugget bathing. GRAND PRISMATIC SPRING, USA I've seen pictures of this spring before, but I didn't reali...