Arriving from Vienna, the Royal train stopped at nyugati pályaudvar (western trainstation).
The waggon for the Royal family stood directly in front of a door, marked with the slogan of King Ferenc József: ‘VIRIBUS UNITIS’.
The slogan still can be found above the door at N 47° 30,666' E 019° 03,455'.
Entering that door the Royals stood in a pavillon used as a waitingroom.
As far as I know this waitingroom was just used twice. If you know more about that spot, please let me know.
The cache is located at the outside of that pavillon where you can find the initials of Ferenc József.