The first railway in Portugal opened in 1856 between Lisbon's Santa Apolónia station and Carregado. With a view to eventual connection with the Spanish network, the Iberian gauge of 1674mm was adopted, which became standard throughout the country.
A few narrow gauge (1000mm) lines remain in operation in the Douro valley. Some other narrow gauge lines in the Porto area which survived into the 21st century have been, or are being, converted to form part of the Porto Metro.
Under EU regulations, train operation and infrastructure costs must be separately accountable. Portugal, like many other European countries, has chosen to implement this by spinning off a separate infrastructure company (REFER). New companies, such as Fertagus, have been created to operate new lines as they are opened.
Until 1925, a narrow gauge rack railway ran up into the mountains from Funchal town, connected to the harbour by a mule tramway.
There was at one time a broad gauge (2140mm) on the island, used for quarrying and breakwater repairs around Ponta Delgada, but it has not operated since the early 20th century. The unusual gauge results from the use of second-hand equipment from the Great Western Railway of Great Britain, which converted its main lines from broad gauge to standard around the end of the 19th century. Subsequent locomotives and rolling stock constructed specifically for the island line were to the same gauge. Some material still remains; a few wagons are on public display and two locomotives (thought to have been lost until rediscovered in a scrap yard in the 1980s) are reported to be in storage pending restoration as museum exhibits.
