Mada’in Saleh, Saudi Arabia

Mada'in Saleh, Saudi Arabia
Qaṣr Al-Farīd tomb photo © Ahmad AlHasanat
 

Also known as Al-Ḥijr or Hegra, this impressive archaeological site belonged in the first century AD to the kingdom of Nabatean, a nomadic Bedouin tribe of the northern Arabian peninsula, whose capital was Raqmu, now known as the famous Petra (Jordan).

According to the Quran, it is believed that this is a cursed place, owing to the punishment with natural disasters given from Allah to the Thamud people (8th century BCE) for their idol worshipping.

The outstanding location consists of 131 rock-cut monumental tombs and was the first Arabian proclaimed UNESCO World Heritage Site in 2008.

The site is reachable by car from the nearest towns with flight connections: al-Wajh (100 km) and al-Ula (20 km).

All visitors need a permit to visit Mada’in Saleh (you can easily obtain the permission in the Hotels near the site).

Impact Craters on Earth

Impact craters on earth are difficult to preserve due to the continuous remodelling of the earth’s crust by orogenesis, plate tectonics and atmospheric agents.

There are around 180 recognizable impact craters on earth, of which about 60 are now buried under sediments, a considerably lower number, for example, compared to the 360.000 craters on Mars or the 7.000 on the moon.
This thanks to the shield made by the earth’s dense atmosphere.
 
Some of them have caused catastrophes, such as the meteorite that carved the Chicxulub crater in Mexico: according to the theory currently accepted by the scientific community postulated by the physicist Luis Álvarez and his son geologist Walter Álvarez, is widely thought to have caused 65 million years ago the end of the dinosaurs due to a tsunami and dust emissions which totally covered the earth’s surface a cloud of dust for many years.


Others have instead brought wealth as the
Popigai crater in Russia, whose impact transformed graphite into diamonds within about 13 km radius.

List of the biggest impact craters on earth:

1. Vredefort Dome, South Africa: 160 km diameter, 2.02 billion years old.
2. Chicxulub crater, Mexico: 150 km diameter, 65 million years old. 
3. Sudbury crater, Canada: 130 km diameter, 1.85 billion years old.
4. Popigai crater, Russia: 100 km diameter, 35 million years old. 
5. Manicouagan crater, Canada: 100 km diameter, 214 million years old.
6. Acraman crater, Australia: 90 km diameter, 580 million years old.
7. Chesapeake Bay crater, USA: 85 km diameter, 35 million years old.
8. Morokweng crater, South Africa: 70 km diameter, 145 million years old.
9. Kara crater, Russia: 65 km diameter, 70 million years old.
10. Beaverhead crater, USA: 60 km diameter, 600 million years old.

Wikimedia map link

Well preserved impact craters on earth:
 
Aouelloul crater, Mauritania
3,1 million years old, 390 m diameter, 53 m depth.


Tenoumer crater, Mauritania
30.000 years old, 1,9 km diameter, 100 m depth.

The Roter Kamm crater, Namibia
5 million years old, 2,5 km diameter, 130 m depth.

Lonar crater lake, India
50.000 years old, 1,2 km diameter, 137 m depth.

Monturaqui crater, Chile
One million years old, 460 m diameter, 34 m depth.

Gosses Bluff crater, Australia
142 million years old, 6 km diameter, 180 m depth.

Pingualuit crater, Canada
1,4 million years old, 3,44 km diameter, 270 m depth.

Amguid crater, Algeria
100.000 years old, 450 m diameter, 30 m depth.

Wolfe Creek crater, Australia
300.000 years old, 875 m diameter, 25 m depth.

Barringer crater, USA
40.000 years old, 1,2 km diameter, 170 m depth.

Barrancos de Gebas, Spain

Located in the southeast of Spain, between the city of Murcia and the Sierra Espuña Regional Park, the Barrancos de Gebas is one of the most fascinating landscapes in Spain.

The semi-desert area, reminiscent of the American badlands, has a lunar landscape characterized by spectacular gullies, canyons and the turquoise waters of the Embalse de la Rambla of Algeciras.

the White Desert, Egypt

The Sahara el Beyda, well known as the White Desert, is one of the most spectacular deserts in the world. Its chalk rock formations, after millions of years of wind and sand erosion, have bizarre shapes like, for example, the rock named “The chicken and the mushroom”.

The area is a National Park located about 50 km North of the town of Farafra, Egypt.

The desert was also the location of the music video of the song Echoes, the first single released by the British rock band Klaxons, from their second studio album, Surfing the Void.

Unfortunately, due to the armies and Islamist militant presence, the area is not safe, though local agencies organize trips for tourists.

Tassili n’Ajjer Nat. Park, Algeria

Tassili n'Ajjer
© Arche Caracalla

The Tassili n’Ajjer National Park, UNESCO World Heritage Site since 1982, is an outstanding plateau of about 70.000 km² composed mostly of black and red sandstone that, due to the erosion, has spectacular shapes of canyons, natural rock arches and volcanic ridges.

The National Park, located in the south-eastern area of Algeria at the borders of Mali, Niger and Libya, reachable from the town of Djanet, is one of the most important archaeological sites in the world, with a well-preserved collection of remains and over 15,000 rock engravings and drawings dating back to the Neolithic era.