Here are wild facts about the Amazon rainforest you may not have heard.

It is believed that there are more than 2.5 million insect species in the Amazon. In addition, more than half of the world's 10 million species of plants, animals and insects are found in this rainforest.

There are many Amazonian tribes that have never had contact with the outside world.

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

Another river that lies beneath the Amazon River is called the Rio Hamza. It is 4 km deeper than the Amazon River. Many people call it the gateway to hell because it lies so deep underground.

The Amazon River mouth is so wide that it could surround an island the size of Switzerland.

The Amazon River once flowed into the Pacific Ocean, but it has changed direction.

There is an Amazon fish called the Arapaima that weighs about 140kg and is covered in an armor-like substance, to protect its body.