City in northeastern Iran with 140,000 inhabitants (2009 estimate), in the Razavi Khorasan province. The name means "Burial place of Heydar"; refecting Qotboddin Heydar, a Sufi mystic. The previous name was Zaveh. In the 19th century it was called Torbat-e Ishaq Khan. The region is among richest in the world in producing saffron.