Earth

Earth, also called Planet Earth or the Real World, is the planet where most of the main characters of the  series, both canon and fanon, originate. It is home to the human species, the only sentient species on the planet. A group of humans from Earth were accidently transported to Narnia during Narnia's creation, and begin the human species in Narnia as well. People from Earth can access Narnia at random times, or specifically through the Wood Between the Worlds. In Narnia, Earth is known as the "World of the Sons of Adam and Daughters of Eve".

England
England is the home of the Pevensies as well as the home of the other travelers. England is part of the United Kingdom of Great Britain (UK) and the capital is London, where the Pevensies, Digory and Polly lived.

London is one of the mentioned places in the Chronicles. The others being the house of Digory Kirke, the school of Eustace and Jill and the appartment of Digory after he had not enough money and lost his house.

Germany
Nazi Germany was referenced in "They were sent to stay with a professor because of the air raids."

United States of America
The United States has been referenced a few times in canon.

World War II
World War II, shortened WWII, was the one mentioned major event to occur on Earth during the lives of the Pevensies and the other travelers. It lasted from 1939 until Sept. 1945.

This major event was predicted by Aslan to Digory and Polly along with the Cold War that followed.