Victoria Falls are located on the Zambezi River on the border between Zimbabwe and Zambia. The falls plummet 108 metres, creating a mist that is visible from 20km away. 

The Dallol volcano in north-east Ethiopia forms part of the Great Rift Valley. It is the world's largest rift system and stretches 6,000km from the Red Sea to Lake Malawi. The valley is up to 75km wide in places and it is cradled by cliffs. 

The incredible honeycomb rock formations of the Giant's Causeway in Northern Ireland look like they were carved out by a stonemason. People once believed the rocky peninsula was the handiwork of an angry giant. 

This marble-clad mausoleum is considered the most beautiful building in the world. 

The Terracotta Army is a collection of terracotta sculptures including more than 8,000 soldiers, 130 chariots and 670 horses. The life-size clay army was buried with Qin Shi Huang, the first Emperor of China. Their purpose was to protect the emperor in his afterlife.

This magnificent 6,500km wall weaves across mountaintops and plunges deep into canyons. The Great Wall is a series of fortifications made of stone, brick, tampered earth, wood and other materials.

The Ngorongoro crater, at 610 metres deep and covering 260 sq km, is the largest unflooded caldera in the world. It is a haven for endangered wildlife and maasai livestock. 

Kilauea is the most active volcano in the world and been constantly erupting for over three decades, creating the fastest-growing piece of land on the planet. 

The Hagia Sophia in Turkey was once a cathedral and a mosque and is now a museum in Istanbul. The building was transformed into a museum in 1935. 

Potala Palace in Tibet is the spiritual home of the Dalai Lama. The architectural wonder is 13 storeys high and at 3,700m above sea level, it is the world's highest palace.