In Pest, arguably the most important sight is Andrássy út. This Avenue is an elegant  long tree-lined street that covers the distance from Deák Ferenc tér to the Heroes Square. On this Avenue overlook many important sites. It is a UNESCO World Heritage Site. As far as Kodály körönd and Oktogon both sides are lined with large shops and flats built close together. Between there and Heroes' Square the houses are detached and altogether grander. Under the whole runs continental Europe's oldest Underground railway, most of whose stations retain their original appearance. Heroes' Square is dominated by the Millenary Monument, with the Tomb of the Unknown Soldier in front. To the sides are the Museum of Fine Arts and the Kunsthalle Budapest, and behind City Park opens out, with Vajdahunyad Castle. One of the jewels of Andrássy út is the Hungarian State Opera House. Statue Park, a theme park with striking statues of the Communist era, is located just outside the main city and is accessible by public transport.