Petén is a department of the nation of Guatemala. It is geographically the northernmost department of Guatemala, as well as the largest in size — at 12,960 square miles (33,600 km²) it accounts for about one third of Guatemala's area. The capital is Flores. The population in 2005 was estimated at 450,000.

The Petén department is bordered on the east by Belize and by Mexico on the north and west, with the Mexican state of Chiapas to the west, Tabasco to the northwest and Campeche to the north. To the south it borders the Guatemalan departments of Alta Verapaz and Izabal. Much of the western border with Mexico is formed by the Usumacinta River and its tributary the Salinas River. Portions of the southern border of the department are formed by the rivers Gracias a Dios and Santa Isabel.

The main bodies of standing water in the department are the lakes Petén Itzá, Peténchel, Quexil, Salpetén and Macanche in the centre of the department; Yaxhá and Sacnab in the east, Petexbatún in the southwest, and Perdida, Larga, La Gloria, San Diego, Mendoza, El Repasto and Lacandón in the west.

Father Pedro Castellanos (1902–1961) was a priest and architect who gained renown in the state of Jalisco during a time of early Modernism marked by sacred purity. He is best known for designing the homes of the Rébora and Aranguren families in Guadalajara.

He was born in 1902 in Guadalajara, to a family that excelled in literature and politics. His grandmother was poet Esther Tapia, and his father was Guillermo Castellanos Tapia, governor of the state of Jalisco.

Castellanos studied at Ambrosio Ulloa’s Engineering School, obtaining a degree in engineering and architecture in 1924. His first job was collaboration with Arnulfo Villaseñor in the construction of José Guadalupe Zuno (at the intersection of Bosques and Union).

By 1925 he was already a lead designer at the office of Juan José Barragán, a prominent builder of the time (he replaced Luis Barragán, who had left to open shop on his own). Around 1931, Pedro Castellanos founded Castellanos and Negrete, leading to a series of brilliant solutions to professional commissions.