The brief answer to this would be that the Safavid Empire was located, more or less, in what is now Iran. The Safavid Dynasty ruled that area for about two centuries. It started around 1500 AD and continued in power until about 1720.
Although most of the land of the Safavid Empire was in what is now Iran, it held some parts of what are now Iran's neighbors. For example, it controlled land as far to the east as Kandahar in what is now Afghanistan. It also controlled land to the north, such as what is now Azerbaijan.
Please follow the link for an image of the extent of the empire.