() with part of the forum on the reverse, marked: and showing the decorative statuary The Forum consisted of a sequence of open and enclosed spaces, beginning with the vast
portico-lined
piazza measuring long and wide, with
exedrae on two sides. The main entrance was at the south end of the piazza, through a
triumphal arch at the center commemorating the Dacian Wars, decorated with friezes and statues of Dacian prisoners. The arch was flanked by tall walls built from blocks of
Peperino tuff clad entirely in marble, which enclosed the Forum on three sides. The tuff walls which enclosed the piazza to the west and east featured exedrae; outside the exedrae, separated by streets, were markets of concentric shape. The three-story eastern market, known as
Trajan's Market, buttressed the excavated edge of the Quirinal Hill. Between the Basilica Ulpia and the terminal piazza containing the temple, were two libraries, one housing Latin documents and the other Greek documents. Between the libraries stood the
Trajan's Column. Trajan's successor
Hadrian added a philosophical school adjacent to the piazza containing the Temple of Trajan. The building consisted of three parallel halls separated by annexes and was known as the
Athenaeum; it functioned variously as school, a venue for judicial proceedings, and an occasional meeting-place for the Senate.
Constantius II, while visiting Rome in the year 357, was amazed by the huge equestrian statue of Trajan and by the surrounding buildings: ==Post-Roman history==