There are many reasons to travel by train in Greece. First of all, one may get to see areas that are not accessible by other forms of public transport. For example, the Nestos River which divides easternmost Macedonia from Thrace (in the northeastern-most part of Greece) has fabulous stretches through canyons popular with white-water enthusiasts, that are served exclusively by the Greek railway.
Another reason to travel by train is that it brings one more in touch with the local people, especially the older trains, which have a more open and casual feeling to them. Travelling on such trains can also bring one in touch with an older way of life that still exists in rural Greece. The little train stations in villages along the way are usually lovely old stone buildings. Lastly, trains are usually cheaper than buses, and the inter-city trains are definitely faster.
Except for the Athens-Piraeus Electric Railway , commonly known to Athenians as the 'ilektriko ' (which is the old train system still in place, and which now connects with the newer metro system), both of which serve the larger Athens area, the outer Greek railway system is administered by the Hellenic Railways System which has the acronym OSE This system was founded in 1971.
There are four different track width gauges used: standard (1.43m), narrow(1m), 75 and 60cm. The rail network consists of 2,484 km/1540miles of mostly single track railway. During the late 1980s major improvements were made, with better signalization, double track rights-of-way, and major tunnelling work, as well as the addition of some more modern trains and passenger rolling-stock.