Interesting and useful websites:

 

https://www.examenglish.com/

http://www.perfect-english-grammar.com/grammar-exercises.html

https://www.merriam-webster.com/word-games

http://locatestreet.com/

https://www.ted.com/

https://kahoot.com/explore-games/

https://www.khanacademy.org/

https://www.google.com/culturalinstitute/beta/

https://www.futurelearn.com/

https://www.howstuffworks.com/

https://www.smithsonianmag.com/