Una volta andavo in quella biblioteca per studiare.

[morbrorper]

It seems a bit contradictory to see imperfect tense along with “una volta”, but I suppose it’s about “there was a time when I used to …”.

[Floria7]

Sì sì that’s how I read it. A dopo…

[Dcarl1]

English Translation

I used to go to that library to study.

Once I did (used to do) X…
This is the same structure as “c’era una volta…”