Together with its 137 metres (448 ft) high south tower, the coloured roof of St. Stephen’s Cathedral is one of the symbols of Vienna. It is considerably tall too (reaches 38 metres, or 125 feet, above the ground) and very steep. Thanks to its steepness the roof is rarely covered by snow and is very clean compared to roofs of other cathedrals, as rain can wash is easily. It is 111 metres (361 ft) long, but it is not its size what makes the Cathedral’s roof so popular.The roof of the Viennese Cathedral is not as boring as roofs of some other churches. It is an artwork by itself. The roof is made of 230,000 glazed tiles of different colours which form various mosaics and patterns. On the south side of the roof (above the choir) the mosaics represent the double-headed eagle, symbol of the Austrian empire under the rule of the Habsburgs. On the north side there are another two eagles, this time each with only one head. These eagles carry the coats of arms of the City of Vienna and of the Republic of Austria, respectively.