The Underground Stairs is a location in the Resident Evil 2 remake.
At the bottom area of this room is a S.T.A.R.S. weapon case that requires the S.T.A.R.S. Badge to be opened, this case gives the Long Barrel (Lightning Hawk) to Leon and the Suppressor (MQ-11) to Claire. Once the badge is placed onto the case, it can still be retrieved back in order to turn it to the USB Dongle Key.
To the left of the weapon case is a door that leads to the Sewers, but it's locked from the other side.
The player must make their way from this room to the Machinery Room to progress, but coming back to this area or the Police Station in general from the Sewers is optional.