A view inside the Sé de Lisboa, Lisbon Cathedral, a Roman Catholic church. Its construction began in 1147 and has since been modified several times surviving several earthquakes. It has been classified as a National Monument since 1910.
The Lisbon tramway network, in operation since 1873, presently comprises six urban lines. In 1901 the network was electrified. The decline of the network began with the construction of the Lisbon Metro but the six remaining lines are still very important as sections of the city's topography can only be crossed by small trams.
