Where are the holy doors in Rome?

The opening of the Holy Door of St. Peter's Basilica in the Vatican marks the beginning of the Jubilee.
That of San Pietro is one of the six papal basilicas that enjoy the highest rank within the Roman Catholic Church. Four of these are located in Rome and are the largest, the other two considered minor are located in Assisi.

The major basilicas have a papal altar and a holy door that is opened only for the duration of a Holy Year with a special rite by the Pope or by a person in charge of him.

The role of the holy door is the granting of the plenary indulgence while the papal altar is used by the Pope or a few other priests to celebrate the Eucharist.

The four major basilicas of Rome are: the St. Peter's Basilica in the Vatican, Archbasilica of St John Lateran, Basilica of St. Paul Outside the Walls and Basilica of St Mary Major.

Until the mid-nineteenth century, the Basilica of San Lorenzo Outside the Walls was also considered a papal basilica but due to a Constantinian basilica that was nearby it was referred to as a major basilica in the broad sense. It has a papal altar, but not having a holy door it is not called a major basilica.

St. Peter's Basilica in the Vatican

It is located in St. Peter's Square in the Vatican City and is the largest among the papal basilicas in Rome.
Inside there are some of the most beautiful works in the world performed by artists such as Bramante and Michelangelo.

Archbasilica of St John Lateran

It is the cathedral of the diocese of Rome and is the oldest and most important basilica in the West. It rises in the vicinity of Mount Celio.

Basilica of St. Paul Outside the Walls

It is also known as Basilica Ostiense from the name of the neighborhood where it is located, it is the largest Roman basilica after St. Peter's in the Vatican

Basilica of St Mary Major

It is also known as the Liberian Basilica and is the only basilica in Rome to have preserved the primitive early Christian structure.
It is located in Piazza dell'Esquilino, between the Rione Monti and the Esquilino.