A gallery is a place that has permanent exhibitions of works of art in it.
...an art gallery.
...the National Gallery.
A gallery is a privately owned building or room where people can look at and buy works of art.
The painting is in the gallery upstairs.
A gallery is an area high above the ground at the back or at the sides of a large room or hall.
A crowd already filled the gallery.
The gallery in a theatre or concert hall is an area high above the ground that usually contains the cheapest seats.
They had been forced to find cheap tickets in the gallery.