These are some of the towers of St. Stephan's Cathedral (Stephansdom in German) in Vienna, Austria. I visited this city last June 2007. I considered this city as a must to visit in Europe if ever you had the chance. We only had a one day sightseeing here which I think not really enough to discover this city. her are some information of this Cathedral..courtesy of Wikipedia.
"St. Stephen's Cathedral is the mother church of the Archdiocese of Vienna and the seat of the Archbishop of Vienna, Christoph Cardinal Schönborn, OP. Its current Romanesque and Gothic form seen today, situated at the heart of Vienna, Austria in the Stephansplatz, was largely initiated by Rudolf IV and stands on the ruins of two earlier churches, the first being a parish church consecrated in 1147. As the most important religious building in Austria's capital, the cathedral has born witness to many important events in that nation's history and has become one of the city's most recognizable symbols.
THE TOWERS OF ST. STEPHEN'S CATHEDRAL
Standing at 136 meters tall (445 ft) and affectionately referred to by the city's inhabitants as "Steffl" (a diminutive form of "Stephen"), St. Stephen's Cathedral's massive south tower is its highest point and a dominant feature of the Vienna skyline. Its construction lasted 65 years, from 1368 to 1433. During the Siege of Vienna in 1529 and again during the Battle of Vienna in 1683, it served as the main observation and command post for the defense of the walled city, and it even contains an apartment for the watchmen who, until 1955, manned the tower at night and rang the bells if a fire was spotted in the city. At the tip of the tower stands the double-eagle imperial emblem with the Habsburg-Lorraine coat of arms on its chest, surmounted by a double-armed apostolic cross, which refers to Apostolic Majesty, the imperial style of kings of Hungary.
The north tower was originally intended to mirror the south tower, but the design proved too ambitious, considering the era of Gothic cathedrals was nearing its end, and construction was halted in 1511. In 1578 the tower-stump was augmented with a renaissance cap, nicknamed the "water tower top" by the Viennese. The tower now stands at 68 meters tall (223 ft), roughly half the height of the south tower.