He is often referred to as "the grandfather of Costa Rican archaeology" for his significant work at Guayabo de Turrialba and other sites in the Central Highlands region of that country.
In 1962, Aguilar joined the faculty of the University of Costa Rica, where he was one of the founders of the Department of Anthropology and also helped with the creation of the Laboratory of Archaeology.
[7] In 1974, he published research on zoomorphic monoliths at Guayabo de Turrialba and began fieldwork at the site of El Monito.
[9] The Americanist anthropology today published his article over his research on the early presence of copper in the Central Intermontano of Costa Rica in 1980 and in 1981, the Preservation Press published an article over his research on two case studies of archaeological parks: Guayabo de Turrialba in Costa Rica and El Caño in Coclé, Panama.
[11] In 1966 Aguilar won the Cleto González Víquez Prize for Religion and Magic of the Indians of Southern Origin of Costa Rica.