Thanks for your help. The map is now translated into English, Spanish, French, Romanian, Sweden, Ukrainian and Nepali. It would be great to have all the languages before 1st September.
In the last days I have improved the map and added some new features, like a small gallery of recent uploaded files and more fields in the marker popups. Also, a counter of monuments with/out images in the shown area.
Now, when an image is only available in a local Wikipedia and not in Commons, it is displayed correctly too.