Metro Line M4 (Budapest Metro) Metro Line M4 (Budapest Metro) Line 4 (officially: South Buda–Rákospalota (DBR) Line, Metro 4 or M4, and unofficially: Green Line), is the fourth line of the Budapest Metro. It opened on 28 March 2014. The first section, 7.4 km in length and consisting of ten stations, connects the southwestern Kelenföld vasútállomás located in Buda, and the eastern Keleti pályaudvar in Pest, under the River Danube. While three additional sections — one an eastern extension to Bosnyák tér, the second west to Virágpiac, and a third further east to Újpalota — have been planned, these remain unfunded by the Budapest city
Budapest the city. Special vehicles in Budapest, besides metros, include suburban rails, trams and boats. There are a couple of less common vehicles in Budapest, like the trolleybus on several lines in Pest, the Castle Hill Funicular between the Chain Bridge and Buda Castle, the cyclecar for rent in Margaret Island, the chairlift, the Budapest Cog-wheel Railway and children's railway. The latter three vehicles run among Buda hills. The culture of Budapest is reflected by Budapest's size and variety. Most Hungarian cultural movements first emerged in the city. Budapest is an important center for music, film, theatre, dance and visual art.