In Celtic mythology, Mag Mell ("plain of joy"), also called Tir na n-Og ("land of youth"), was the underworld. Unlike the underworld in most mythologies, Mag Mell was a pleasurable paradise, either an island or at the bottom of the ocean.
... Cross tube station (for the Jubilee Line)
Holborn tube station (for the Aldwych branch of the Piccadilly Line)
These stations once served by the Metropolitan Line, ...