You're looking for a Mint Tin, so bring your own pen or pencil.
This is a very high muggle area, so the challenge is find, sign and replace without attracting attention.
Lots of security guards, police and workers also in this area.
Please make sure you place it back exactly where you found it.
Please don't let us down.
Congratulations to Jack Dalton and Philippluca for FTF.