thanks for you comments,
@hawkeye As I have not the skills and time to look deeper into a software I tried the tourism tag option you mentioned and it´s ok for me. see
https://mongolianstreetart.wordpress.com
I'll try maperative later.

@vclaw for the overlays one should probably have a website stored on a server and be the admin to upload add-ons etc. beside the content. in my case I only use a simple weblog.