In Mauritania, northwestern Africa, slavery is a fact of modern life. It's estimated that 10-20 percent of the country's 3.5 million people are still enslaved in a system rooted in ethnic discrimination.
The Hagia Sophia in Istanbul has become a bone of contention. Since it was secularised in 1935, it has been a museum. Now Turkish nationalists want to turn it back into a mosque - while the Patriarch of Constantinople wants to use it as a church again. A photo essay by Klaus Dahmann.