View looking east at the northern portion of the Eastern Portico of the Forum of Augustus. Three steps lead up to the Portico. In the center of the image part of the semicircular exedra is visible. This wall, of peperino, was originally covered with marble, of which some slabs were inscribed with the deeds of Augustus called the res gestae.
The paving of the portico, visible in the center of the image, was made up of Italian grey, Numidian yellow and "Lucullan" red/black marble!
Left of center, on the flat wall made out of blocks of tuff (peperino) that were originally covered with marble, the outline of the roof and indentations for roof beam are visible.
To the left of that the gate, with white marble steps leading up to it, opened into a slum of Rome called the Subura, to the north. On the dark grey tuff walls, note the horizontal white stripes of travertine marble. This sturdy wall was constructed to protect the forum in case a fire broke out in slum, Subura, to the north of it!
The small building fragment in the lower left of the image is a corner of the Temple of Mars Ultor.