Historic site — Pythio, near Didymoteicho, ~1.5 hours north of the city
Built in 1873 by the same French company, Chemins de fer Orientaux, that built Alexandroupolis's own station, Pythio sits at the junction where the branch line to Ormenio and Bulgaria splits from the main Thessaloniki–Istanbul route.
Its odd claim to fame is border geography: after the 1923 Treaty of Lausanne fixed the Evros River as the Greek–Turkish frontier, trains leaving Pythio for Bulgaria — the Orient Express among them — had to cross into Turkey at Edirne and back into Greece again before reaching the border, a loop that only ended in 1971 once a new line let trains bypass Greece entirely on Turkish soil.
The late 19th-century station buildings themselves have been recognised for their architectural value and restored with platform-level access, though as of this writing services run as a rail-replacement bus following nationwide safety changes to Greek rail — check current status before planning a visit around the train itself.