Naples is a very hilly city, the perfect public transport solution therefore is the funicular or cable railway. Naples has four. The Chiaia was the first, built in 1889, then the Montesanto, followed by the Central and the Mergellina. The Central is one of the longest funicular in the world, and one of the busiest, carrying over 10 million passengers a year. It was built in 1928.
The most famous was the Mount Vesuvius funicular built in 1880. It was the first one built on an active volcano and was damaged by eruptions at various times until finally being destroyed by the 1944 eruption. The famous Neapolitan song Funiculi Funicula was dedicated to it.