The Capitol Hill (Colle del Campidoglio), which nowadays hosts the Municipality of Rome, was the eldest fortress in Rome and here was the Temple of Jupiter. The current arrangement of the Piazza belongs to the XVI century and was prepared by Michelangelo Buonarroti, who planned two of the palaces delimiting three sides of the square, the wide stairway who leads to the top of the hill on the fourth side and the geometric drawing on the ground floor, built in recent times following the original project. In the middle of the square was placed the equestrian statue of emperor Marcus Aurelius, now replaced by a copy.

The three palaces (Palace of Conservatori, Palace Nuovo and Palace Senatorio) host the Musei Capitolini (Capitoline Museums) with a plentiful collection or archaeological remains of ancient Rome. There are: the original equestrian statue of Marcus Aurelius; remains of gigantic statue of Constantine; mosaics from the Villa Adriana (Hadrian's Villa) in Tivoli; the statue of Capitoline Venus; the Hall of the Emperors, with more than 70 bust portraits; statues of Centaurs; the statue of Drunken Faun; the statue of dying Galata, by the school of Pergamus from 2nd century b.C.; the renown bronze statue of Lupa Capitolina (Capitoline she-wolf), symbol of the Republic of Rome; the statue of Esquiline Venus. Inside the Capitoline Museums there is also a painting gallery with paintings by Tiziano, Caravaggio, Guido Reni, Pietro da Cortona.

On top of the stairway to the Capitol Piazza there are the statues of Dioscuri, belonging to the imperial age and rediscovered in the XVI century: they show Castor and Pollux standing side by side their horses. In the square there are also the so-called Trophies of Marius. celebrating the victory by Domitian over Germans, and the Milestone columns, originally placed along the Via Appia, respectively signaling the 1st and the 7th miles. Aside the piazza there is the Church of Santa Maria d'Aracoeli, with a steep entrance stairway which ast as a counterpoint to the plain and classical stairway by Michelangelo.