 In 1998 his research on architect Rogelio Salmona was published in both Spanish and English, and he exhibited photographs of Salmona's work at Galeria Mundo (Bogotá) in 2001.During the early 2000s, Castro was also Director of Research at the Institut de recherché en histoire de l’architecture (IRHA) in Montreal.At that time he partnered with Nicholas Olsberg of the Canadian Centre for Architecture to research the work of Canadian architect Arthur Erickson.