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 regional offices, including the United Nations and ICDT, furthermore it is the headquarters of the European Institute of Innovation and Technology, the European Police College and the first foreign office of the China Investment Promotion Agency. Over 40 colleges and universities are located in Budapest, including the Eötvös Loránd University, Semmelweis University and the notable Budapest University of Technology and Economics. Opened in 1896, the city's subway system, the Budapest Metro, serves 1.27 million, while the Budapest Tram Network serves 1.08 million passengers daily. Budapest is cited as one of the most beautiful cities in Europe, ranked as "the world's