Moonlit Rail ™

Ruined Archways

Grassy Nave York Minster Former Nave
Ruined archways, Saint Mary's Abbey, York, England

These archways are all that remains of Saint Mary's Abbey, save for the pillar bases set amidst the grass. What the author would like to know is: where does that darkened doorway (at the right-hand base of the central arch) lead to? There are no obvious openings elsewhere in the structural remains.