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 in the city, for instance deserve to mention the most well-known Prezi, LogMeIn or NNG. Budapest is the highest ranked Central and Eastern European city on Innovation Cities' Top 100 index. A good indicator of the city's potential for innovation and research also, is that the European Institute of Innovation and Technology chose Budapest for its headquarters, along with the UN, which Regional Representation for Central Europe office is in the city, responsible for UN operations in seven countries. Moreover, the global aspect of the city's research activity is shown through the establishment of the European Chinese Research Institute in