Right across the piazza from St. John Lateran is part of the old Lateran palace, which houses the 28 marble steps that were climbed by Christ to the praetorium of Pilate when he was judged. They were brought from Jerusalem in the 300's by St. Helen, mother of the Emperor Constantine. Today they are covered by protective wood casing, and are climbed on one's knees.
A close up of the marble steps seen throw the windows in the wood.
Also cut into the wood are little windows through which you can view stains of Christ's blood.
At the bottom of the stairs are several beautiful statues depicting scenes from Christ's passion. Here is the agony in the Garden of Gethsemane.
And lastly Judas the traitor betraying Christ with a kiss.