Question: The Basilica San Paolo station is located behind a Basilica that is commonly known as what?
Context: The Papal Basilica of St. Paul outside the Walls (Italian: "Basilica Papale di San Paolo fuori le Mura" ), commonly known as St. Paul's outside the Walls, is one of Rome's four ancient, Papal, major basilicas, along with the Basilicas of St. John in the Lateran, St. Peter's, and St. Mary Major. San Paolo Maggiore, also known as San Paolo Decollato, is a Baroque-style, Roman Catholic basilica church located on Via Carbonari #18 in Bologna, region of Emilia-Romagna, Italy. The Roma–Lido railway is an urban railway line connecting the Porta San Paolo Station in Rome to Lido di Ostia, Rome's seaside neighborhood. Basilica San Paolo is a station on the Line B of the Rome Metro.  It was opened in 1955 and is located behind the Basilica of Saint Paul Outside the Walls (after which it is named) in the Ostiense quarter.  It is also one of three Metro stations also served by the Rome-Lido railway line. Alatri Cathedral, otherwise the Basilica of Saint Paul (Italian: "Duomo di Alatri" ; "Basilica concattedrale di San Paolo apostolo"), is a Roman Catholic cathedral in Alatri, Lazio, Italy, dedicated to Saint Paul.  It was formerly the cathedral of the Diocese of Alatri.  Since 30 September 1986 it has been a co-cathedral of the Diocese of Anagni-Alatri.  Pope Pius XII declared it a basilica minor on 10 September 1950. The Patriarchal Cathedral Basilica of Saint Mark (Italian: "Basilica Cattedrale Patriarcale di San Marco" ), commonly known as Saint Mark's Basilica (Italian: "Basilica di San Marco" ; Venetian: "Baxéłega de San Marco" ), is the cathedral church of the Roman Catholic Archdiocese of Venice, northern Italy.  It is the most famous of the city's churches and one of the best known examples of Italo-Byzantine architecture.  It lies at the eastern end of the Piazza San Marco, adjacent and connected to the Doge's Palace.  Originally it was the chapel of the Doge, and has only been the city's cathedral since 1807, when it became the seat of the Patriarch of Venice, archbishop of the Roman Catholic Archdiocese of Venice, formerly at San Pietro di Castello. The Rome Porta San Paolo Railway Park Museum is a museum in Rome (Italy), concerned with railway and tram transportation.  It is housed next to the Roma Porta San Paolo railway station and the Piramide station of the metro (line B). Mission Basilica San Juan Capistrano is a Catholic parish in the Diocese of Orange in California.  The parish church is located just northwest of Mission San Juan Capistrano in the city of San Juan Capistrano, California, United States.  Completed in 1986, it was designated a minor basilica in 2000 and a national shrine in 2003. The Basilica of Saint Praxedes (Latin: "Basilica Sanctae Praxedis" , Italian: "Basilica di Santa Prassede all’Esquillino" ), commonly known in Italian as Santa Prassede, is an ancient titular church and minor basilica in Rome, Italy, located near the papal basilica of Saint Mary Major.  The current Cardinal Priest of "Titulus Sancta Praxedis" is Paul Poupard. Roma Ostiense is a railway station in Piazza dei Partigiani serving the Ostiense district of Rome, Italy, a short distance from the Porta San Paolo.  It is run by the Centostazioni arm of the Ferrovie dello Stato group and the urban rail lines FR1, FR3, and FR5 run through the station.  It is linked with the Piramide Metro B station and the Roma Porta San Paolo station on the Rome-Lido railway line.
Answer: St. Paul's outside the Walls