Aloba Arch

알로바 아치

Aloba Arch is a giant natural arch in the Ennedi Plateau, a sandstone region in northeastern Chad that lies inside the Sahara Desert. It is about 120 metres tall, which makes it one of the tallest natural arches known, and much taller than the more famous Rainbow Bridge in Utah.

See it on the 3D globe →

At a glance

Country: Chad
Location: Ennedi Plateau, Chad
Height: 120 m

Quick answers

Where is Aloba Arch?

Aloba Arch is in Ennedi Plateau, Chad.

How tall is Aloba Arch?

Aloba Arch is about 120 m tall.

A colossal sandstone arch about 120 metres high in the Ennedi Plateau of the Sahara, one of the largest natural arches in the world.

Its span, the distance across the opening, is estimated at roughly 76 metres. That estimate comes from photographs, because the arch is remote and was only recently recognised for its size. By span it ranks about eighth in the world, and it is the longest arch outside China and Utah. The Ennedi Plateau has a geology similar to the Colorado Plateau, so wind and water have carved arches, towers and cliffs here too.

How a stone arch forms

Sandstone is made of grains of sand pressed and cemented together. Over a very long time, rain, flash floods and blowing sand wear away the softer layers while harder rock above remains. A hole slowly opens up and grows into an arch. The same process made arches on the Colorado Plateau in the United States. Chad's Ennedi Plateau is the Sahara's example, and Aloba is its biggest arch.

A hard place to reach

Large natural arches are rare outside southern and western China and the Colorado Plateau. Aloba is far from roads and towns, and it was only recently recognised for its size, so its exact measurements are still estimates. The tallest measured arch span so far is Xianren Bridge in China, at about 122 metres across. The Ennedi region is also known for rock art and for being a UNESCO site.

Fun facts

Aloba Arch is about 120 metres tall, taller than a 35-storey building.
Its span is estimated at about 76 metres.
It is the longest natural arch outside China and Utah.
The arch stands in the Sahara but is made of sandstone like the American Southwest.