John Seifert's architectural and Interiors company in England, Sigma, has just completed the Corinthia, the leading luxury hotel, apartment and spa complex in London, which has opened to high acclaim. The firm's luxury Conrad resort in Portugal's Quinta do Lago will also open shortly. Other recent completions include the refit of the Hilton and Crowne Plaza in Bucharest. Work continues on major projects in London, Munich and Moscow as well as on the Marriott in Krasnodar and Sofitel in Kiev. Sigma has a number of very experienced specialist designers who have worked with John Seifert over many years. They provide guidance and support for his other international architectural companies.