Triumphal columns and archers?

[Aymer de Valence]

In my Greek campaign i've recently started conquering the Italian peninsula, and in some of the larger cities like Rome and Capua, as well as the blacksmiths etc there are triumphal columns and several archers dotted around the city streets. I've played 2 long Roman campaigns in the past, and never got an option to build them? Do they just appear randomly and can other civilisations have them too? (or at least a civilisation specific monument such as an Egyptian needle)

[Equilibrius]

They are simply a part of the standard city background, their presence is determined by the city size alone and are automatically placed.