Robot Museum

The Robot Master Museum is, as its name suggests, a facility introduced in Mega Man 7 that stores a number of Robot Masters.

Mega Man 7
Doctor Albert W. Wily attacked the museum and stole a copy of Guts Man from it that he modified in order to create Guts Man G.

Mega Man (Archie Comics)
Dr. Light placed those Robot Masters created by Dr. Wily and Ra Moon who chose to be shut down rather than repurposed in the Robot Master Museum as displays.