Pedro Adolfo de Castro Besosa (1895-1936) was born in Brooklyn to Pedro De Castro (1867-1928) from Ceiba and Manuela “Mima” Besosa (1872 - 1963) from Ponce. His family moved back to Puerto Rico when he was five years old. In 1914 he enrolled at Syracuse University, graduating in 1918 with a degree in architecture. Upon graduation he returned to Puerto Rico and started working at the Puerto Rico Department of the Interior in San Juan, under the direction of Puerto Rico State Architect Adrian Finlayson. During his two-year tenure there, he collaborated in the design of the Puerto Rico Capitol building and the Escuela Superior Central in Santurce, both credited to Finlayson. In 1921 he worked with Antonin Nechodoma where he designed not only buildings but also lamps, mosaics, furniture, and other products.

Among his most notable designs are the Castillo Serrallés (1926) and the Jacobo Cabassa (1934) residence since demolished, both in Ponce. Some of his work not pictured below include:

• Casa de España, Ponce de Leon Ave., San Juan, Puerto Rico (de Castro, Pedro), NRHP-listed[11]

• Castillo Serrallés, Cerro El Vigia, Ponce, Puerto Rico (de Castro, Pedro Adolfo), NRHP-listed[11]

• Edificio Victory Garden, 1001 Ponce de Leon Ave., corner of Elisa Colberg St., San Juan, Puerto Rico (De Castro, Pedro), NRHP-listed[11]

• House at 659 La Paz Street, 659 La Paz St., Miramar, Puerto Rico (De Castro, Pedro), NRHP-listed[11]

• House at 663 La Paz Street, 663 La Paz St., Miramar, Puerto Rico (De Castro, Pedro A.), NRHP-listed[11]

• Jacinto Lopez Martinez Grammar School, Calle Norte and Calle San Quintin, Dorado, Puerto Rico (de Castro, Pedro Adolfo), NRHP-listed[11]

• Casa Villa Caparra, Carretera PR-19 intersección PR-2 No. 251, Guaynabo, Puerto Rico (de Castro, Pedro Adolfo), NRHP-listed[11]

De Castro Besosa died at the age of 41 when his small airplane crashed on 18 October 1936. His son Pedro A. de Castro Gayá (1919- ) also became an architect designing among others the Ponce YMCA Building.