English moves around with little words: in, out of, into. Finnish puts the movement into an ending — and for every place there are three questions:

Question	Ending	Example	English
Missä? — where?	-ssa / -ssä	Olen kahvilassa.	I'm in the café.
Mistä? — where from?	-sta / -stä	Tulen kahvilasta.	I'm coming out of the café.
Mihin? — where to?	vowel + n	Menen kahvilaan.	I'm going into the café.

You already know the first two: Olen Helsingissä, Olen Bostonista. These three are the inner cases — for being inside something: buildings, rooms, cities, countries.

The new one is the into ending, called the illative. Minne? means the same as mihin? — you'll hear both.