Osh is the most convenient place to head towards Tashkent, the capital of Uzbekistan and the largest city in Central Asia. The road, apart from border crossing and currency exchange, lasts approximately 5-6 hours (depending on whether your driver is a Formule-1 racer in his imagination). There are two options for getting from Osh to Tashkent: car or train. Both options have their pros and cons.
