The present Treasury Building was built over a period of 33 years between 1836 and 1869. The east and center wings, designed by Robert Mills, architect of the Washington Monument and the Patent Office Building, comprise the first part of the building constructed between 1836 to 1842. The most architecturally impressive feature of the Mills design is the east colonnade running the length of the building. Each of the 30 columns is 36 feet tall and is carved out of a single piece of granite. The interior design of the east and center wings is classically austere, in keeping with the Greek Revival style.
Later additions were made to the original wings, beginning with the construction of the south wing from 1855 to 1860 and the west wing from 1855- 1864. The preliminary design of the wings was provided by Thomas Ustick Walter, architect of the Capitol dome, but architects Ammi B. Young and Isaiah Rogers refined the plans, designed the interior details, and supervised construction. While the exterior of the building was executed along the lines of the original Mills wings, the interiors of the later wings reflect changes in both building technology and aesthetic tastes. Iron columns and beams reinforced the building's brick vaults; the architectural detailing became much more ornate, following mid-nineteenth century fashion. The final addition to the Treasury Building was the north wing, built from 1867 to 1869. Its architect was Alfred B. Mullett. Similar in construction and decor to the south and west wings, the north wing is unique as the site of the Cash Room -- a two-story marble hall in which the daily financial business of the U.S. Government was transacted. The room opened in 1869 as the site of President Grant's inaugural reception.
The Treasury Building is the oldest departmental building in Washington and has had a great impact on the design of other governmental buildings. At the time of its completion, it was one of the largest office buildings in the world. It served as a barracks for soldiers during the Civil War and as the temporary White House for President Andrew Johnson following the assassination of President Lincoln in 1865. The Treasury Building is unquestionably a monument of continuing architectural and historical significance. In acknowledgment of the building's significance, Treasury was declared a National Historic Landmark in 1972.
Guided tours of the building are available free of charge. The tour features restored spaces such as the 1864 Burglar-Proof Vault and the marble Cash Room. Also on the tour is the restored office of Salmon P. Chase, Secretary of the Treasury during the Civil War and the temporary office used by President Andrew Johnson following Abraham Lincoln's assassination, which has been restored to its 1860s appearance.References:
The Petersberg Citadel is one of the largest extant early-modern citadels in Europe and covers the whole north-western part of the Erfurt city centre. It was built after 1665 on Petersberg hill and was in military use until 1963. It dates from a time when Erfurt was ruled by the Electors of Mainz and is a unique example of the European style of fortress construction. Beneath the citadel is an underground maze of passageways that can be visited on guided tours organised by Erfurt Tourist Office.
The citadel was originally built on the site of a medieval Benedictine Monastery and the earliest parts of the complex date from the 12th century. Erfurt has also been ruled by Sweden, Prussia, Napoleon, the German Empire, the Nazis, and post-World War II Soviet occupying forces, and it was part of the German Democratic Republic (East Germany). All of these regimes used Petersberg Citadel and had an influence on its development. The baroque fortress was in military use until 1963. Since German reunification in 1990, the citadel has undergone significant restoration and it is now open to the public as a historic site.