If you aren't on the Orient Express and are on Greek Rail remember trains vary and you get what you pay for. So my advice for those of you going to Turkey on the night train from Thessaloniki or Athens - get a sleeper in advance and try to get an express every where and particularly to Constantinople or Istanbul. Prepare for 2 border customs stops and delays and being woken up.
Thrace province only became part of Greece in 1920. The part of the larger region of Thrace (split between Bulgaria, Greece, and Turkey) is properly called 'Western Thrace', to distinguish it from 'Eastern Thrace', which is the portion of old Thrace in present day Turkey.
The region has a population of about 400,000, with a topography that resembles that of the Balkans more than that of the rest of Greece. The Rhodope mountains form its northern border with Bulgaria, and which are cut by five major river systems which create broad fertile valleys. The Ottoman railway building through here during the late 19th century was urged by military leaders for strategic purposes (moving troops rapidly), with the rail lines avoiding city centers, where they would be more vulnerable, and also because they were more difficult to establish there due to hilltop locations of cities.
Toxotes is an old Turkish Muslim town with mosques and minarets visible from the train. The ugly concrete apartment blocks were thrown up quickly to house Greek refugees from Asia Minor after the 1922 'katastrofi'. About a third of the population of Thrace is Muslim, with the Muslims consisting of Turks, Pomaks and Gypsies ( the latter now properly referred to as Roma). The Pomaks are Bogomil-Christian Slavs who were forced to convert to Islam during the 16th century; the women wear long black veils. Cities in Thrace are clean and have nice squares and old sectors with half-timbered houses with the second floor enclosed balconies typical of Muslim countries. There are more than 300 mosques in the province, co-existing along with Orthodox churches.
East from Toxotes the line bears slightly north, where the forested slopes of the Rhodope mountains are visible, as well as both Greek and Muslim villages; fields are cultivated with tobacco.