Question: Justo Perez Santiago was an abbot of what Monastery that has a memorial in the municipality of San Lorenzo de El Excorial? 

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Monastery of San Martiño Pinario: The monastery of San Martiño Pinario ("San Martín Pinario" in Castilian) is a Benedictine monastery in the city of Santiago de Compostela, Galicia, Spain.  It is the second largest monastery in Spain after San Lorenzo de El Escorial.

Mount Abantos: Mount Abantos (Spanish: "Monte Abantos" ) is a mountain in the Sierra de Guadarrama range in the Sistema Central of Spain, a chain that runs from east to west.  For the most part, the mountain is located in the municipality of San Lorenzo de El Escorial in the Community of Madrid, with part of its west side in the province of Ávila.

San Lorenzo de El Escorial: San Lorenzo de El Escorial, also known as El Escorial de Arriba is a town and municipality in the Community of Madrid, Spain, located to the northwest of the region in the southeastern side of the Sierra de Guadarrama, at the foot of Mount Abantos and Las Machotas, 29 mi from Madrid.  It is head of the same name judicial party.  The settlement is popularly called El Escorial de Arriba, to differentiate it from the neighbouring village of El Escorial, also known as El Escorial de Abajo.

Pinckney's Treaty: Pinckney's Treaty, also commonly known as the Treaty of San Lorenzo or the Treaty of Madrid, was signed in San Lorenzo de El Escorial on October 27, 1795 and established intentions of friendship between the United States and Spain.  It also defined the border between the United States and Spanish Florida, and guaranteed the United States navigation rights on the Mississippi River.  With this agreement, the first phase of the on-going border dispute between the two nations in this region, commonly called the West Florida Controversy, came to a close.

Valle de los Caídos: The Valle de los Caídos (] , "Valley of the Fallen") is a Catholic basilica and a monumental memorial in the municipality of San Lorenzo de El Escorial, erected at Cuelgamuros Valley in the Sierra de Guadarrama, near Madrid, conceived by Spanish dictator Francisco Franco to honour and bury those who died in the Spanish Civil War.  Franco claimed that the monument was meant to be a "national act of atonement" and reconciliation.  The Valley of the Fallen, as a surviving monument of Franco's rule, and its Catholic basilica remain controversial, in part since 10% of the construction workforce consisted of convicts, some of whom were Spanish Republican political prisoners.

San Lorenzo de Almagro (basketball): San Lorenzo de Almagro is the men's professional club basketball section of the San Lorenzo de Almagro multi sports club, that is based in Buenos Aires, Argentina.  The team plays in the Liga Nacional de Básquet (LNB), which is the first tier level division of the Argentine basketball league system.  The team is currently coached by Julio Lamas.  San Lorenzo plays its home games at the Polideportivo Roberto Pando, which is located in Boedo, Buenos Aires.

El Escorial: The Royal Site of San Lorenzo de El Escorial (Spanish: "Monasterio y Sitio de El Escorial en Madrid" ), commonly known as El Escorial (] ), is a historical residence of the King of Spain, in the town of San Lorenzo de El Escorial, about 45 km northwest of the capital, Madrid, in Spain.  It is one of the Spanish royal sites and has functioned as a monastery, basilica, royal palace, pantheon, library, museum, university and hospital.  It is situated 2.06 km up the valley (4.1 km road distance) from the town of El Escorial.

Justo Pérez de Urbel: Justo Pérez Santiago (August 7, 1895 – 1979) later known as Fray Justo Pérez de Urbel y Santiago O.S.B. was a Spanish Roman Catholic clergyman (Order of Saint Benedict) and medievalist, first abbot of the Monastery of the Holy Cross of the Valle de los Caídos, member of the Consejo Nacional del Movimiento (the first quasi-parliamentary assembly of Francoist Spain), later a Procurador en Cortes (member of the longer-lived Francoist assembly established after the end of the Spanish Civil War) and distinguished scholar of medieval Castile.

San Lorenzo de Almagro: Club Atlético San Lorenzo de Almagro, commonly known as San Lorenzo de Almagro or simply San Lorenzo (in English: "Saint Lawrence"), is an Argentine sports club based in the Boedo district of Buenos Aires.  It is best known for its football team, which plays in the Primera División, the first tier of the Argentine football league system.  San Lorenzo is also considered one of the "big five" (""Los 5 Grandes"") of Argentine football by Argentine press, with Independiente, River Plate, Boca Juniors, and Racing Club.

Yanga, Veracruz: Yanga Municipality is a municipality located in the southern area of the State of Veracruz, Mexico, about 80 km from the state capital of Xalapa.  It was formerly known as San Lorenzo de los Negros (after a colony of "cimarrons" in the early 17th century) or San Lorenzo de Cerralvo (after a 17th-century Spanish colonial priest).  In 1932 it was renamed after Gaspar Yanga, the "cimarron" leader who in 1609 resisted attack by Spanish forces trying to regain control of the area.

Supporting paragraphs: Justo Pérez de Urbel Valle de los Caídos
Answer: Valle de los Caídos