To expand on Cosmo's reply, the arch is part of the stone grotto in the park at the entrance to Palmer Union Station.
The park (gradually being restored by the Steaming Tender) was designed by world famous landscape architect,
Frederic Law Olmsted, whose most famous design is probably Central Park in New York City. In fact, the park in Palmer
is now referred to as Olmsted Park. When the station and park restoration are completed, they should be as grand as
when opened some 132 years ago.