Budapest lies in central Hungary . The Danube enters the city from the north; later it encircles two islands, Óbuda Island and Margaret Island[6]. Pest's terrain rises with a slight eastward gradient, so the easternmost parts of the city lie at the same altitude as Buda's smallest hills, notably Gellért Hill and Castle Hill. The Buda hills consist mainly of limestone and dolomite, the water created speleothems, the most famous ones being the Pálvölgyi cave and the Szemlohegyi cave . The hills were formed in the Triassic Era. The highest point of the hills and of Budapest is János hill, at 527 meters above sea level. The forests of Buda hills are environmentally protected. Widely regarded as one of the most beautiful cities in Europe , its World Heritage Sites include the banks of the Danube, the Buda Castle Quarter, Andrássy Avenue, and the Millennium Underground Railway, the first on the European continent. The neo-Gothic Parliament, containing amongst other things the Hungarian Crown Jewels. Saint Stephen's Basilica, where the Holy Right Hand of the founder of Hungary , King Saint Stephen is on display. The Hungarian cuisine and café culture: for example, Gerbeaud Café, and the Százéves, Biarritz , Fortuna, Alabárdos, Arany Szarvas, Kárpátia and the world famous Mátyás Pince Restaurants. There are Roman remains at the Aquincum Museum, and historic furniture at the Nagytétény Castle Museum. The Castle Hill, the River Danube embankments and the whole of Andrássy út have been officially recognized as UNESCO World Heritage Sites. The Holy Crown of Hungary , also known as the Crown of St. Stephen. Castle Hill and the Castle District; there are three churches here, six museums, and a host of interesting buildings, streets and squares. The former Royal Palace is one of the symbols of Hungary ¿ and has been the scene of battles and wars ever since the thirteenth century. Nowadays it houses two impressive museums and the National Széchenyi Library. The nearby Sándor Palace contains the offices and official residence of the President of Hungary . The seven-hundred year-old Matthias Church is one of the jewels of Budapest . Next to it is an equestrian statue of the first king of Hungary , King Saint Stephen, and behind that is the Fisherman's Bastion, from where opens out a panoramic view of the whole city. Statues of the Turul, the mythical guardian bird of Hungary , can be found in both the Castle District and the Twelfth District. In Pest, arguably the most important sight is Andrássy út. 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 Palace of Arts, and behind City Park opens out, with Vajdahunyad Castle. One of the jewels of Andrássy út is the Hungarian State Opera House. Memento Park is a theme park with striking statues of the Communist era. The city is home to the largest synagogue in Europe (Dohány Street Synagogue)[32], the largest medicinal bath in Europe (Széchenyi Medicin