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. Other important sectors include also, as natural science research, information technology and medical research, non-profit institutions, and universities. The leading business schools and universities in Budapest, the Budapest Business School, the CEU Business School and Corvinus University of Budapest offers a whole range of courses in economics, finance and management in English, French, German and Hungarian. The unemployment rate is far the lowest in Budapest within Hungary, it was 2.7%, besides the many thousands of employed foreign citizens. Budapest is among the 25 most visited cities in the world, the city welcoming more than 4.4 million international visitors