Places You Would Never Know Had Volcanoes

The Earth is 4.5 billion years old. It has probably seen millions of volcanoes during its lifespan. Just over the last 10,000 years, about 1,500 have been active on land. Many more on the ocean floor remain unknown, according to the U.S. Geological Survey.

Volcanoes, which are simply openings or vents on the earth's surface, are classified in several groups.[slideshow:86204]

Shield volcanoes are the largest on the planet; stratovolcanoes comprise the largest percentage (60 percent) and often have explosive eruptions; Rhyolite caldera complexes are the most explosive but don't look like traditional volcanoes; and monogenetic fields are collections of many separate vents and flows. There are also flood basalts and mid-ocean ridges.

Some don't even look like there is something underneath. But if they erupt – a phenomenon that is mostly unpredictable – they can trigger tsunamis, and cause flash floods and earthquakes.

The most famous volcanoes are in Hawaii, Italy and South America, which has more than 200 of them. Some are and dangerous, but accessible for hiking enthusiasts and adventurers. Japan, Indonesia, Philippines, Ecuador and Iceland are other countries widely known for their active and dormant volcanoes. But there are also places you may have never heard of, where lava lakes are hiding underground.

Click here to see Places You Would Never Know Had Volcanoes

More readings: 

Most Incredible Active Volcanoes You Can Actually Hike Around the World

The Most Dangerous Volcanoes on Earth

The Most Dangerous Camping Destinations