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 nonprofit Budapest Festival and Tourism Center at its info-points. The info centers also offer the Budapest Card which allows free public transit and discounts for several museums, restaurants and other places of interest. Cards are available for 24-, 48- or 72-hour durations. The city is also well known for its ruin bars both day and night. Budapest has many municipal parks and most have playgrounds for children and seasonal activities like skating in the winter and boating in the summer. Access from the city center is quick and easy with the Millennium Underground. Budapest has a complex park system,