15.4.2 exercise 2: The preposition a to designate a movement towards a place
In the case of cities, countries and regions there is no distinction between the movement and the residence at a place.
In the case of countries and regions in is to be used in both cases (Vado in Italia / Sono in Italia) in the case of cities the preposition a is used in both cases (Vado a Roma / Sono a Roma).
For the generic nouns city, country, region the same rule applies (Vado in città / Sono in città).
In all other cases in is only used when we speak about the residence in some place.
But if we talk about a movement we have to distinguish. If the stress in on the function of a building (city hall, church, train station etc.) the movement is to be described with in (Vado in municipio / I go to the city hall).
But if the stress is on a concrete building, this happens for instance if it is described more in detail, the movement is described with the preposition a (Vado al municipio di Senigallia per parlare con il Sindaco / I go to the city hall of Senigallia to talk with the mayor).
Some nouns doesn' t fit in this rule. In the case of casa / home, scuola / school, università / university, parco / parc, teatro / theater the stress in on the function and not on the building ( so the movement should be described with in following the rules above), but nevertheless we say vado al teatro / I go to the theater and Sono a casa / I am at home. In simple terms: Casa (in the sense of at home), parco, teatro, università works the same way as cities.