* Molen could be a misspelling of "Molen", which is a Dutch word meaning "mill".
* Avenue is the correct spelling of the word "avenue".
To determine if "Molen Avenue" is spelled correctly, you need to tell me:
* What city or town is this avenue located in?
* Is there any other information about the avenue, such as a street number or nearby landmarks?
Once I have more information, I can help you verify the spelling.