|Covid-19|date unknown - Work begins on the East India Company's Plantation House in Saint Helena, which remains the official residence of the Governor.
New church of the Abbey of St Genevieve in Paris, designed by Jacques-Germain Soufflot and finished by Jean-Baptiste Rondelet, is completed to serve as the Panthéon.
Estrela Basilica in Lisbon.
Royal Observatory in Madrid, designed by Juan de Villanueva.
The Pitot House, New Orleans built by Don Santiago Lorreins (bought by James Pitot in 1809).
The John Dodd Hat Shop in Danbury, Connecticut, built by lawyer John Dodd.
The bridge at Warwick Castle, England.
Monmouth County Gaol, U.K., designed by William Blackburn.
November 7 - Karol Podczaszyński, Polish neoclassical architect (died 1860)
date unknown - John Hawks, American architect (born c.1731)
1790 in architecture Wikipedia
The year 1790 in architecture involved some significant architectural events and new buildings.