The reason for normalizing things like County or Division is so that if you need to change the county's or division's name you can change it in one place, not dozens or hundreds. Also, it ensures that whenever a county is listed, it is spelled the same for each and every entry.
Given that the location of the monuments isn't likely to change, the only reason to do it is to make sure that you don't have a country entered in lots of nearly the same but slightly different ways (i.e. Broward, broward, BROWARD, Browrd etc.)
In this case you probably don't need to normalize the table down to that level. But if it works better that way then go for it. Using the right kind of indexing on primary keys will keep the performance quite good, even on heavily normalized data under most dbms systems.
