Linha do Norte is the Portuguese main railway track that connects the two main Portuguese cities, Lisbon

Lisbon

Lisbon is the capital city and largest city of Portugal with a population of 545,245 within its administrative limits on a land area of . The urban area of Lisbon extends beyond the administrative city limits with a population of 3 million on an area of , making it the 9th most populous urban...

 and Porto

Porto

Porto , also known as Oporto in English, is the second largest city in Portugal and one of the major urban areas in the Iberian Peninsula. Its administrative limits include a population of 237,559 inhabitants distributed within 15 civil parishes...

. In its 314 km, it crosses some other important cities like Vila Franca de Xira

Vila Franca de Xira

Vila Franca de Xira is a municipality in Portugal with a total area of 317.7 km² and a total population of 133,224 inhabitants. Situated on the west bank of the Tagus River, just 32 km north-east of the Portuguese capital Lisbon, Vila Franca de Xira is said to have been founded by French...

, Santarém

Santarém, Portugal

Santarém is a city in the Santarém Municipality in Portugal. The city itself has a population of 28,760 and the entire municipality has 64,124 inhabitants.It is the capital of Santarém District....

, Entroncamento, Pombal

Pombal, Portugal

Pombal is a town in Pombal Municipality, Portugal. The population of the city is about 16.000 inhabitants....

, Coimbra

Coimbra

Coimbra is a city in the municipality of Coimbra in Portugal. Although it served as the nation's capital during the High Middle Ages, it is better-known for its university, the University of Coimbra, which is one of the oldest in Europe and the oldest academic institution in the...

, Aveiro, Espinho

Espinho, Portugal

Espinho is a city in Espinho Municipality in Portugal. It is a reputed beach resort and a zone of legal gambling with a casino - Casino Solverde. Its fair - Feira de Espinho, having been first organised in 1894, is well known in Portugal...

 e Vila Nova de Gaia

Vila Nova de Gaia

Vila Nova de Gaia, or simply Gaia is a city in Vila Nova de Gaia Municipality, Portugal. It is located in the Porto District, south of the city of Porto on the other side of the Douro River. The city proper has a population of 178,255 and the municipality contains 24 parishes with a total...

, among others. It's the backbone of the Portuguese railway system of freights and passengers, running daily hundreds of wagons of both types.

Soon it'll have a parallel high-speed line (up to 300 km/h) to relieve this main line, since it has reached a saturation threshold where it's impossible to add new freight wagons without jamming the fast passenger services (InterCidades and Alfa Pendular

Alfa Pendular

Alfa Pendular is the name of the Pendolino high-speed tilting train of Portuguese state railway company CP. It connects the cities of Braga, Porto, Aveiro, Coimbra, Santarém, Lisbon, Albufeira and Faro, among others at speeds of up to ....

).