An extension to the already protected area of the Buda Castle; if you cross the Lánchíd to the Pest side, you get to Andrássy út which leads to Heroes' Square. After the unification of Pest, Buda and Óbuda (1873) the city started to develop dynamically. This development took place at the same time as the process of preparing for the 1000th anniversary of the Magyar conquest of Hungary (896). Heroes' Square and the group of buildings called Vajdahunyad Castle situated behind it in Városliget were completed by the Millennium. The statues of outstanding Hungarian rulers and leaders stand in the semicircular colonnade. On the two sides of the square there are the Museum of Fine Arts and the Műcsarnok (Art Gallery) standing opposite each other. Andrássy út was built on the basis of a uniform architectural concept. The City Centre section is lined with 3-4-storey, eclectic, Neo-Renaissance apartment buildings. Its central section is wider; here the road is divided into three parts, the main road has a service road on either side, which are separated from the main road by a pavement lined with trees. The two service roads were originally covered with wooden blocks, and the aristocrats could ride their horses here. The third section is lined with apartment blocks, which have front gardens and with large villas built in parks. Some of the outstanding buildings are the Opera, the Ballet Institute, the old Music Academy and the graffito corner house of Kodály körönd. Under the avenue there is the Millennium Underground Railway, which was the first underground railway on the continent.