Beneath Vatican City lies a Roman cemetery where Peter was buried in AD 64; above it rise 500 years of papal ambition. Three days tracing the necropolis, the Borgo, Castel Sant'Angelo and the archives that made this the world's smallest state.
The Roman street of mausoleums buried by Constantine in AD 320, excavated 1940-49. Ends at the Trophy of Gaius and bone fragments identified as Peter's. Ufficio Scavi bookings only, by email, months ahead; 15 people per group.
The floor level of Constantine's 4th-century basilica, holding 91 papal tombs from Hadrian IV to John Paul I. Look for the Renaissance sarcophagi salvaged when Old St. Peter's was demolished in 1506, plus Queen Christina of Sweden.
Clement XIV's 1771 antiquities wing, built around the Laocoön group unearthed on the Esquiline in 1506 and bought by Julius II within hours. The Octagonal Court also holds the Apollo Belvedere and Belvedere Torso Michelangelo studied.
Founded by Gregory XVI in 1837 from digs in the Papal States' Etruscan south. The Regolini-Galassi tomb finds from Cerveteri (c. 650 BC) — gold fibula, bronze bed, chariot — are the richest intact Etruscan burial ever recovered.
Hadrian's mausoleum of AD 139, turned papal fortress and prison. Clement VII fled along the 800m Passetto wall during the 1527 Sack of Rome while his Swiss Guard died on the basilica steps. Open 09:00-19:30, closed Mondays.
Where Mussolini and Cardinal Gasparri signed the Lateran Pacts on 11 February 1929, creating Vatican City and ending the 59-year 'Roman Question' after Italy seized the Papal States in 1870. The signing table stands in situ.
A 120m corridor frescoed 1580-83 by Ignazio Danti for Gregory XIII: 40 topographical maps of the Italian peninsula, plus the papal fleet at Lepanto. It is the largest geographical picture cycle in the world and a record of pre-unification Italy.
The corps arrived 22 January 1506 under Julius II. New recruits swear their oath every 6 May, the date 147 guards fell in 1527. The barracks flank the working border gate where Vatican number plates and Annonario deliveries cross daily.
Pius XI's 1932 gallery of 460 works in 18 chronological rooms. Raphael's Transfiguration hung above his coffin in 1520; Leonardo's unfinished St. Jerome was found split in two, the head used as a stool top by a Roman cobbler.
The surviving grid of the medieval Borgo, laid out by Pius IV in the 1560s inside the Leonine Walls that Leo IV raised in 852 after Saracen raiders sacked Old St. Peter's. Cobbled Via Borgo Pio still runs on its Renaissance alignment.
Julius II's private apartments, painted 1508-24. The School of Athens gives Plato Leonardo's face and Heraclitus Michelangelo's; the Fire in the Borgo records the 847 blaze Leo IV stopped with a blessing from the Loggia.
Founded 727 as the Schola Saxonum hostel for Anglo-Saxon pilgrims, rebuilt by Innocent III in 1198 as Europe's first modern hospital. Its rota degli esposti — a rotating barrel for anonymous infant abandonment — survives in the wall.