Known as Waiahuakua, this is the second longest sea cave in the world, stretching 1,155ft. It is known as the Sacred Water Cave and as the Double Door cave – as it has both an entrance and an exit. Kayak tours run through the cave to allow visitors a close-up view of the caverns huge length. A fissure in the roof of the volcanic rock allows water to gush into the amazing cavern.
The Fingal's sea cave in the Hebrides Islands of Scotland is a huge natural formation, discovered in the 17th century and called after an Irish legendary hero. Impossible not to feel like the hero of a tale walking its surroundings.