Question: What is the name of the Austrian architect known for designing the historic building complex in Austria known as The Belvedere?
Context: The 21er Haus or Einundzwanziger Haus (English: House 21 ) is a modernist style steel and glass building designed by Austrian architect Karl Schwanzer (1918–1975).  Originally constructed as the Austrian pavilion or temporary showroom for the Expo 58 in Brussels, it was later transferred to Vienna to house the Museum of the 20th Century, which explains why it was first nicknamed "20er Haus" ("House 20").  Between 1979 and 2001, the building also acted as a depository for contemporary art works.  From 2009 to 2011, it was remodeled by the architect Adolf Krischanitz and consequently renamed 21er Haus to reflect the 21st century. Belvedere Palace Chapel is a chapel located in the south eastern corner tower of the Upper Belvedere in Vienna, Austria.  It was designed by the Austrian architect Johann Lukas von Hildebrandt. Johann Lukas von Hildebrandt (14 November 1668 – 16 November 1745) was an Austrian baroque architect and military engineer who designed stately buildings and churches and whose work had a profound influence on the architecture of the Habsburg Empire in the eighteenth century.  After studying in Rome under Carlo Fontana, he constructed fortresses for Prince Eugene of Savoy during his Italian campaigns, becoming his favorite architect.  In 1700 he became court engineer in Vienna, and in 1711 was named head of the court department of building.  He became court architect in 1723.  His designs for palaces, estates, gardens, churches, chapels, and villas were widely imitated, and his architectural principles spread throughout central and southeast Europe.  Among his more important works are Palais Schwarzenberg, St. Peter's Church, and Belvedere in Vienna, Savoy Castle in Ráckeve, Schönborn Palace in Göllersdorf, and Schloss Hof. The Urbana-Lincoln Hotel – Lincoln Square Mall is a historic building complex located at 300 South Broadway Avenue in Urbana, Illinois.  The Tudor Revival style hotel was built in 1923.  In 1964, the mall was built as an extension of the hotel; it was one of the first fully enclosed shopping malls in Illinois.  Both the hotel and the mall are still in operation, and the building complex was listed on the National Register of Historic Places in 2006. Hannes Lintl (2 July 1924 – 13 June 2003) was an Austrian architect, best known for designing the Donauturm ("Danube Tower", 1964), part of the Viennese skyline and a popular lookout point and tourist attraction. The Belvedere is a historic building complex in Vienna, Austria, consisting of two Baroque palaces (the Upper and Lower Belvedere), the Orangery, and the Palace Stables.  The buildings are set in a Baroque park landscape in the third district of the city, on the south-eastern edge of its centre.  It houses the Belvedere museum.  The grounds are set on a gentle gradient and include decorative tiered fountains and cascades, Baroque sculptures, and majestic wrought iron gates.  The Baroque palace complex was built as a summer residence for Prince Eugene of Savoy. Béthanie () is a historic building complex located in Pok Fu Lam, in Hong Kong built in 1875 as a sanatorium by the Paris Foreign Missions Society (French: "Missions Étrangères de Paris" ).  It is a Grade II historic building. The Sidney Yates Building, formerly called the Auditors Building Complex, at 14th St. and Independence Ave. in Washington, D.C., and originally built as the Bureau of Engraving and Printing, is an historic building complex built in 1878–1880.  It is Romanesque in style and was designed by the office of James G. Hill. Martin William Ashley MVO Dipl Arch RIBA (born 29 April 1952) is a British architect known for restoration of ecclesiastical buildings and royal properties and a specialist in period and listed buildings.  He studied a Diploma in Architecture at Kingston Polytechnic and completed a scholarship with Society for the Protection of Ancient Buildings in 1976.  He worked for Purcell Miller Tritton and became a partner before setting up his own business, Martin Ashley Architects, in 1994.  From 1999 to present, Martin Ashley has held the post of Surveyor of the Fabric St Georges Chaple, Windsor.  In 2011 Martin Ashley was honoured with Member of the Royal Victorian Order He is an architect member of Guildford Diocesan Advisory Committee, and lectures on the philosophy and principles of historic building conservation. Margarete "Grete" Schütte-Lihotzky (January 23, 1897, Margareten bei Wien, Austria-Hungary – January 18, 2000) was the first female Austrian architect and a communist activist in the Nazi resistance movement.  She is mostly remembered today for designing the so-called Frankfurt kitchen.
Answer: Johann Lukas von Hildebrandt