Problem cliff, historic ruins do not appear on the map when you mark them

Can you give an example of something that doesn't appear? The browser URL bar should be good enough if you zoom in.

Also - note that there are lots and lots of different renderings of OSM data, there's not one "the map". There are actually 5 different renderings on the openstreetmap.org site - click the "stack of books" icon at the right-hand side to choose between them.

Also, even the map on osm.org doesn't get updated immediately: https://help.openstreetmap.org/questions/178/how-often-does-the-main-mapnik-map-get-updated

In addition to the 5 renderings @SomeoneElse mentions, there are lots of other specialized renderings, including the Historical Objects map which may be useful for your purposes: http://gk.historic.place/historische_objekte/translate/en/index-en.html