July 19 - The Paris Métro opens, with entrances designed by Hector Guimard in 1899.
Antoni Gaudí begins work on the Parc Güell, which he works on for the next fourteen years.
The Gare d'Orsay, the modern-day Musée d'Orsay, is built in Paris by Victor Laloux.
The Joseph Chamberlain Memorial Clock Tower at the University of Birmingham, England, is completed.
The OXO Tower in London, England, is completed.
The Royer Printing House, designed by Lucien Weissenburger, is completed.
Alexander Nevsky Cathedral, Tallinn, designed by Mikhail Preobrazhensky, is completed.
Dohodno Zdanie, Rousse, Bulgaria.
Villa Schutzenberger in Strasbourg, France, is completed.
Kinloch Castle on the isle of Rùm, Scotland, designed by Leeming & Leeming, is completed.
Bullough Mausoleum on the isle of Rùm, Scotland, built (approximate date).
Victoria Theatre, Salford, England opens.
Royal Gold Medal - Rodolfo Amadeo Lanciani.
Grand Prix de Rome, architecture: Paul Bigot.
February 6 - Paul László, Hungarian-born architect (died 1993)
March 23 - Hassan Fathy, Egyptian architect (died 1989)
April 5 - Herbert Bayer, Austrian-born graphic designer (died 1985)
October 8 - Geoffrey Jellicoe, English landscape architect (died 1996)
November 3 - Guillermo Gonzalez Sanchez, Dominican architect (died 1970)
February 23 - William Butterfield, English ecclesiastical architect (born 1814)
April 16 - Dankmar Adler, German American architect (born 1844)
June 2 - Charles Barry, Jr., English architect (born 1823)
August 18 - Edward Habershon, English ecclesiastical architect (born 1826)
1900 in architecture Wikipedia
The year 1900 in architecture involved some significant events.