Balkh is a province in northern Afghanistan. Its capital, Mazar-e-Sharif, is the country's second largest city. Most of its northern border is with Uzbekistan, although it also touches Turkmenistan and Tajikistan. It has provincial borders with Jowzjan, Samangan, and Kunduz. The Amu Darya River flows through the province. It is crossed by the Friendship Bridge, from Termez in Uzbekistan.