Welcome to where east meets
Turkey is home to the second oldest subway in the world: Istanbul's Tünel. Despite the fact that it's no stranger to the worldwide light rail revolution, it also sports many "Tünels" in villages and towns, some built over a thousand years ago. While most are empty of subways, they may warrant your exploration.
Plans for light rail in Isparta and Samsun are on hold due to financial problems...I mean issues.