Alexandroupolis is a small town with a harbour and an airport. Though the Lonely Planet describes it as "dusty", it has a rocky beach, and a typical Greek nightlife.
There are several trains from Thessaloniki. Slow trains take 6h (9€), fast ICs take only 4 1/2h (16€).
Train connections are frequent to the rest of the country, though the rail-link toward Bulgaria via Dikea has been canceled still further notice. Trains are running only to Dikea, 15km of the Bulgarian border. No buses to the border city of Svilengrad, taxi and hitchhiking being the only options to acces Svilengrad and the extensive Bulgarian rail network.
National Network of Buses or KTEL operates a frequent schedule of buses to all the major cities of the country. Shutle buses depart twice daily to Athens (approximately 8–9 hours) and there are hourly connections to Thessaloniki.
OSE, the national train operator, has set a daily bus shuttle to Istanbul that departs the main station early (around 7AM) every morning. Tickets are usually easy to find and can be booked in the ticket office.
There are no cheap youth hostels, but a couple of mid-range hotels by the seaside. Backpackers often just stay at the beach near the train station.