He is probably best known for his large sculpture of Antonio de Montesinos delivering his sermon at the seafront of Santo Domingo in the Dominican Republic (1982) and the geometrical cubic forms he added to the St. Peter's Basilica in the Vatican (1977).
In 1963-4 he studied drawing at the Escuela Nacional de Artes Plásticas and painting and sculpture at the Instituto Nacional de Bellas Artes, and was apprenticed to his stepfather sculptor Federico Canessi in the 1960s and 1970s.
[3] In May 1977, Antonio Castellanos, Ricardo Cruz and Fundatier Galindo contributed the geometrical cubic forms in the St. Peter's Basilica in the Vatican.
[4] Castellanos is noted for his large sculpture of Antonio de Montesinos delivering his sermon facing the Caribbean sea at the seafront of Santo Domingo in the Dominican Republic.
[6] Castellanos is also noted for his "monumental head" of Diego Rivera at the Dolores Olmedo Museum in Mexico City In 1967 Castellanos was awarded an Award of Honor for his sculpture "Germinación" at the Biennial Museum of Modern Art in Mexico City.