The Gate was constructed between 1788 & 1791 according to the designs of its architect, Carl Gotthard Langhans. The Gate itself is built in sandstone & consists of twelve Doric columns, six to each side, forming five passageways. Citizens originally were allowed to use only the outermost two, the central passageway being reserved for Prussian royalty & visiting foreign dignitaries. Though the Brandenburg Gate has remained essentially unchanged since its completion, it has had a turbulent existence. In 2000, the Berlin Monument Conservation Foundation began a full restoration of the Brandenburg Gate. It opened to the public again on October 3rd 2002, the twelfth anniversary of German Reunification. Today, Brandenburg Gate is regarded as one of Europe's most famous landmarks.