It is difficult to grasp the immense size of the interior of St. Peters, until one is actually inside the Nave.
To give some idea of scale, here a priest is walking across the area of the church where the nave joins the north and south transepts, an area known as the "crossing".
This gives some idea of the scale of the church as well as that of the monumental bronze Baldechino designed by Bernini.
In the background on the right center, is Bernini's sculpture of Longinus in one of the niches of the great piers
that hold up the dome of St. Peters. The sculpture is about 17 feet tall.
The side of the Baldechino can just be seen on the far left side of the picture.