Hello, and welcome to Wikipedia! Thank you for your efforts to improve the encyclopedia. I see that you keep trying to add "Athens" to the article Largest cities in Europe. And you don't understand why people keep removing it. Here is why: the list is based on the population within the city limits. According to this reference , the population of Athens within the city limits is only 665,000. The figure of 3.75 million that you want to use is the population of the whole metropolitan area. So please don't keep adding Athens. It is a large and important city, but its population is not high enough to be listed in this article. Thanks for your interest in improving Wikipedia! If you have any questions, you can ask me here.