James Street Station on the Liverpool Underground which opened in 1886.
The nice new shiny side is platform 3, the other side platform 2, which is rarely used, is more or less as it was constructed many years ago.
It does have a 50 metre long frieze, by Tim Chalk and Paul Grime, which resembles an archaeological relic.
This station, and Hamilton Square, across (or below), the river in Birkenhead, are the oldest deep-level underground stations in the world.
I am not sure quite how deep they are, but in Birkenhead, instead of taking the lift, I walked up the 162 steps back to street level.