The section of the Museum dedicated to the Forum of Trajan is found in the lower section of the Markets of Trajan. This area, which lies under the so-called Exedra Arborea Garden, was covered by ground works in reinforced cement in the 1930’s but as a result of the damage suffered from over 70 years of use, a radical reorganisation and restoration project was required. Another exhibition space is dedicated to the internal decorations of the Basilica Ulpia and the Western Libraries and it too hosts the ruins of the buildings to which it once belonged.
Now, a large reassembly of an entrablature (frieze-architrave) is displayed here. The exhibit is in a space that is in direct contact with the remains of the building to which it once belonged - the two lateral frontal halls of the Great Hemicycle.