This is the view of the castle (through a telephoto lens) from the Vilnius University bell-tower which is part of the church of St John the Baptist and St John the Evangelist (Šv. Jonų bažnyčia).
You can get into the tower either from the university or by a gate on Šv. Jono g..
The tower is the tallest building in the Old Town at 68 m and the 360 view over the city is stunning (on a fine day; when it rains not so much).
On the lower panoramic photo you can just see the Hill of Three Crosses and how heavily wooded the city is.