The Main Line starts from Colombo and runs east and north past the rapidly developing centres of Ragama, Gampaha, Veyangoda, and Polgahawela.

Between Balana and Kadugannawa, the track clings to the side of sheer cliffs, offering passengers views of Batalegala ('Bible' Rock).

The Main Line then continues its climb through tea country, connecting local market centres at Gampola, Nawalapitiya, and Hatton before reaching Nanu Oya.

The Main Line continues its ascent to the summit at Pattipola, 1,898 m (6,227 ft) above sea level, before descending past Bandarawela to Badulla.

The main reason for building a railway system in Sri Lanka (Ceylon) was to transport tea and coffee from the hill country to Colombo.

[4][5] Sri Lanka Railways also began importing new diesel-multiple units to replace the aging rolling stock previously used on the line.

The new S12 trainsets built by China's CSR Corporation Limited in 2012 are designed to work on the steep gradients of the hill country.