principal port serving the city of Porto and northern Portugal. It is an artificial harbour on the Atlantic Ocean, within the town of Matosinhos, 5.5 miles (9 km) northwest of central Porto. Porto is prevented by a sandbar from having a deepwater harbour of its own. The Leixões harbour is formed by two curved breakwaters that are 5,240 feet (1,597 m) and 3,756 feet (1,145 m) long. The port's original docking facilities were completed in 1890 and were subsequently expanded in the early 1930s and early 1970s. While Port of Leixões long has been associated with the export of port wine, Porto's most famous product, at the end of the 20th century, the port's facilities were modernized to provide additional large-scale container-park gantries and new equipment, including heavy cranes, capable of handling Panamax container ships (i.e., ships narrow enough to fit through the Panama Canal).