The Devils Tower – Wyoming
The first declared United States National Monument, it was established in 1906 by President Theodore Roosevelt. The monument got its name in 1875 during an expedition led by Col. Richard Irving Dodge when his interpreter misinterpreted the name to mean Bad God’s Tower, which then became Devil’s Tower.
Gibson Steps (The Twelve Apostles) – Great Ocean Road, Australia
The Twelve Apostles is a collection of limestone stacks off the shore of the Port Campbell National Park, by the Great Ocean Road in Victoria, Australia. The apostles were formed by erosion: the harsh weather conditions from the Southern Ocean gradually eroded the soft limestone to form caves in the cliffs, which then became arches, which in turn collapsed; leaving rock stacks up to 45 metres high.
Cave of the Crystals – Naica, Mexico
The Cave of the Crystals or Giant Crystal Cave is a cave connected to the Naica Mine 300 metres (980 ft) below the surface in Naica, Chihuahua, Mexico. The main chamber contains giant selenite crystals, some of the largest natural crystals ever found.
Door To Hell – Turkmenistan
The Door to Hell is a natural gas field in Derweze, Turkmenistan. It is noted for its natural gas fire which has been burning continuously since it was lit by Soviet petrochemical scientists in 1971, fed by the rich natural gas deposits in the area. The pungent smell of burning sulfur pervades the area for some distance.
Chocolate Hills – Philippines
The Chocolate Hills is a geological formation in Bohol Province, Philippines. There are at least 1,260 hills spread over an area of more than 50 square kilometres. They are covered in green grass that turns brown (like chocolate) during the dry season, hence the name.