National Geographic has a nice online feature called Places Of A Lifetime. It highlights major cities from all over the work sharing information, images, and videos. It also has short and simple quizzes users can take.
The language is accessible to Intermediate English Language Learners, and the images can certainly be viewed by anyone.
Even though it has pages on cities world-wide, most of them appear to be in the United States. Because of that, I’ve placed the link on my website under The United States and Canada.