Wilhelm Sundheim-Giese, better known as Guillermo Sundheim (3 July 1840 – 7 August 1903), was a German entrepreneur and businessman, who is widely regarded as one of the most important figures of Huelva at the end of the 19th century, being responsible for part of the development and economic growth of the province, especially in the financial, mining, and railway fields.

[1][2] In fact, it was he who convinced the director of the London bank, Hugn Matheson, to make large investments in the province of Huelva and purchase those mines, which resulted in the foundation of Rio Tinto Company Limited (RTCL), of which he was a member.

[citation needed] Sundheim set an example of how to take advantage of other natural resources throughout the Huelva region, producing exquisite wines, exploiting magnificent white marble quarries, establishing the breeding and fattening of pigs, and making considerable shipments to England of the famous chestnut from the Sierra.

[2] Sundheim was the owner of the first chalet built in Punta Umbría,[1] and in the early 1880s, he was one of the promoters, together with Matheson and Doetsch of the RTCL, of the construction of Hotel Colón, a luxury hotel meant not only to accommodate the growing number of English and German businessmen and senior executives of the various companies operating in the mining basin of Rio Tinto, but also to provide an infrastructure in Huelva capable of hosting the events celebrating of the fourth Centenary of the Discovery of America, hence its name.

[1] During the so-called Centenary Season, which took place between 3 August and 12 October 1892, Hotel Colón accommodated several important Spanish personalities, such as the Prime Minister of Spain Antonio Cánovas del Castillo and representatives of the invited Ibero-American nations.