I don't see the lists of monuments not static at all.
1) The number of monuments is changing continously. Even there is no exact data I would see the number of monuments added or removed in my country alone at around 1.000 per year. For the US National Register of Historic Places we can see the annual changes in weekly reports http://www.cr.nps.gov/nr/nrlist.htm
2) The information we fetch about the monuments (new descriptions, new geodata, new images) is changing continously and fast.
3) All information about administrative units the monuments are in, is also changing continously. Municipalities get merged, streets get renamed.
If we talk about an ideal scenario, that all monument lists are available in all Wikipedias on a more or less current level, the communities could get to edge of their capacity. In an ideal synergetic scenario the local Wikipedias take care for the monuments of their country, take pictures, add geodata and the updated information (at least the basic global information) is updated in all other Wikipedias without causing too much work.
Lars