Istanbul and Rome have for 2000 years been connected by a route along which soldiers, religions, goods and habits have been transported.

Via Egnatia began from Istanbul and continued through Northern Greece to present day Albania by the Adriatic Sea. In the end of it there was a short sea-voyage to the Italian coast from where Via Appia, the most famous ancient road finally led to Rome.

The Romans started to build Via Appia 300 years BC and Via Egnatia two hundred years later. These roads are considered examples of the excellence of contemporary engineering. Their width was several metres, they were paved with huge flat stones or sand.

Via Egnatia was an important commercial route during the Byzantine and Ottoman Empires also.

Via Egnatia is still an important route, although the parallel between ancient and modern road is not exact (the western section, from Thessaloniki to the Adriatic Sea, runs further south than the ancient road).

Last summer I traveled Egnatia Odos from Thessaloniki to Igoumenitsa - some parts look just breathtaking!

http://www.lonelyplanet.com/greece/travel-tips-and-articles/75919

You can also take a look here