Mauna Loa is located on the Big Island of Hawaii.

It is an active shield volcano.

Mauna Loa is considered one of Earth's most active volcanoes.

It last erupted in 1984.

The volcano is approximately 13,678 feet (4,169 meters) high.

The Great Barrier Reef is the largest coral reef system in the world.

It is located off the coast of Queensland, Australia.

The reef is approximately 2,300 kilometers long.

It is a UNESCO World Heritage site.

Astronauts aboard the International Space Station can see the reef from space.

The Amazon Rainforest covers 5.5 million square kilometers.

It is the largest tropical rainforest in the world.

The rainforest is often referred to as the "lungs of the Earth."

Its trees and plants produce oxygen through photosynthesis.

Around 20% of the world's oxygen is produced by the Amazon Rainforest.

Mount Everest is part of the Himalayas.

It is located on the border of Nepal and China.

The mountain's peak is 8,848 meters (29,029 feet) above sea level.

Climbing Mount Everest is a challenging and dangerous endeavor.

The first successful summit of Mount Everest was in 1953 by Sir Edmund Hillary and Tenzing Norgay.

The Sahara Desert covers an area of about 9.2 million square kilometers.

It is located in northern Africa.

The desert is known for its extreme temperatures and vast sand dunes.

Despite its arid nature, the Sahara is home to some animal and plant species.

The Nile River flows through 11 countries in northeastern Africa.

It stretches for approximately 6,650 kilometers.

The river is crucial for the livelihoods of millions of people living along its banks.

The Nile has played a significant role in the history and development of Egypt.

The Galapagos Islands are located in the Pacific Ocean, off the coast of Ecuador.

The islands are known for their unique and diverse animal and plant species.

During his visit to the Galapagos Islands in 1835, Charles Darwin observed variations in species that led to his theory of natural selection.

The islands are now a UNESCO World Heritage site.

The Grand Canyon is located in Arizona, USA.

It was carved by the Colorado River over millions of years.

The canyon is approximately 446 kilometers long and up to 29 kilometers wide.

It is renowned for its stunning landscapes and rock formations.

The Great Wall of China stretches across northern China.

It is a UNESCO World Heritage site and one of the Seven Wonders of the World.

The wall was built to protect China from invasions and raids.

It is estimated to be over 13,000 miles (21,196 kilometers) long.

The Northern Lights are colorful lights that appear in the sky near the North Pole.

They are caused by interactions between solar particles and Earth's magnetic field.

The lights can vary in color, including green, pink, and purple.

The best time to see the Northern Lights is during clear, dark nights in areas with little light pollution.