The Central Railway Station is the primary hub for domestic and international rail transport, carried out by Bulgarian State Railways (BDZ), the national rail company headquartered in the city. It is one of the main stations along BDZ Line 1, and a hub of Lines 2, 5 and 13. Line 1 provides a connection to Plovdiv, the second-largest city in Bulgaria, while Line 2 is the longest national railway and connects Sofia and Varna, the largest coastal city. Lines 5 and 13 are shorter and provide connections to Kulata and Bankya, respectively. Overall, Sofia has  of railway lines.