Inner South London Line

The Inner South London Line is an 8.5-mile (13.7 km) horseshoe-shaped Inner London railway route from Victoria to London Bridge via Peckham Rye. "Inner" distinguishes it from the Outer South London Line which runs from London Victoria to London Bridge via Gipsy Hill. The line is in Travelcard Zone 2 apart from the termini, which are in Zone 1. Passenger rail services are currently operated by Southern.

It is planned that the current half-hourly London Bridge to Victoria service will cease in December 2012. Instead, most of the line will be incorporated into the London Overground network, diverting westbound services away from Victoria to Clapham Junction to form an orbital rail line around London.

More information on the Wikipedia page