The Melbourne rail network has its origins in privately built lines from the 1850s gold rush era, and today the suburban network consists of 209 suburban stations on 16 lines which radiate from the City Loop, a partially underground metro section of the network beneath the Central Business District (Hoddle Grid). Flinders Street Station is Melbourne's busiest railway station, and was the world's busiest passenger station in 1926. It remains a prominent Melbourne landmark and meeting place. The city has rail connections with regional Victorian cities, as well as direct interstate rail services to Sydney and Adelaide and beyond which depart from Melbourne's other major rail terminus, Southern Cross Station in Spencer Street. In the 2013–2014 financial year, the Melbourne rail network recorded 232.0 million passenger trips, the highest in its history. Many rail lines, along with dedicated lines and rail yards are also used for freight. The Overland to Adelaide departs Southern Cross twice a week, while the XPT to Sydney departs twice a day.

How many lines does the Melbourne rail network have?