Simplify the following text for a Grade 7 native English-speaking person.
Original: Port wine ( also known as Vinho do Porto , Porto , and often simply Port ) is a Portuguese fortified wine produced exclusively in the Douro Valley in the northern provinces of Portugal .
Simplified: Port wine ( also called Vinho do Porto , Oporto , Porto , and often simply Port ) is a Portuguese wine . It comes from the Douro Valley in the northern provinces of Portugal .