The Porta Westfalica is a gorge, where the Weser river runs through the passage between the mountain chains of the Wiehengebirge in the west and the Wesergebirge (part of the Weserbergland) in the east. It is located in the district of Minden-Lübbecke in North Rhine-Westphalia, Germany.
The name "Porta Westfalica" is Latin language term, and means "Gate to Westphalia". Coming from the north, the gorge is the entry to the region of Westphalia. Despite the Latin name the term was not coined in Roman times, but by scholars of the 19th century.
High above the gorge on the west side is a large six-sided stone structure that can be seen from a considerable distance; this is the Emperor William Memorial, erected in honour of Kaiser Wilhelm I and dedicated in 1896.