The land was granted at the turn of the 18th century by Governor Willem Adriaan van de Stel to a rich merchant, Reynier Smedinga. Tradition has it that Smedinga, who had previously been a ship's captain, brought out the building materials necessary for the job on his last voyage to the Cape, and used them in 1701 to build for himself a thatched cottage on the site.
The house was given its present form by architect Louis Thibault who, during the mid-18th century, turned it into a double-storey mansion with a flat roof and so-called Louis XVI architectural features. It was acquired by the De Wet family in 1809 when it was purchased by the widow of Hendrik de Wet. She and with her three sons lived in this residence for many years, and it eventually passed to her eldest son, Johannes, who was an advocate and played a leading role in the public life of Cape Town.
Among the many eminent men who visited his house were Abraham Faure, Andries Stockenstrom and John Fairbairn. De Wet had two daughters, one of whom, Marie, married Johan Koopmans, an officer in the British German Legion who emigrated to South Africa after the Crimean War. After the death of Koopmans in 1880, the two sisters continued to live in the house, and it was during this time that Marie Koopmans de Wet emerged as a powerful political figure in the Cape, taking a leading role in Cape society. She took a particular interest in the preservation of historical buildings and objects, and is credited with saving both the Castle in Cape Town and the Powder Magazine in Stellenbosch from demolition. Under her patronage, she held an influential salon and numbered personalities such as Cecil Rhodes, Sir John Truter and Presidents Kruger, Brand, Reitz and Steyn amongst her visitors.
After the death of the sisters in 1906 and 1911 respectively, the house, together with its most important contents was purchased by the State by means of public subscription, and was handed over to the Trustees of the South African Museum in Cape Town. It was declared a National Monument under old NMC legislation on 1 November 1944. This historic house, situated in Cape Town's City Center, was one of the first private residences to be opened to the public. Today iziko Koopmans-de Wet House is one of the six sites of the South African Cultural History Museum, and is well known for its unique wall paintings. The home also contains valuable collections of porcelain, glass, furniture and art works. The house was originally built in 1700 and its facade, a fine example of neoclassical architecture, dates back to the late 18th century. Check website for details.0.