On the north-east side of via dei Fori Imperiali are the extensive remains of Trajan's forum, the last of the fora, laid out in the early second century AD. At the northern extremity of this forum rises the white marble colonna traiana (Trajan's column), an amazingly well-preserved work of Roman sculpture, dedicated in AD 113 to celebrate the triumph over the Dacians. The spiral reliefs, containing over 2,500 figures, depict the campaigns against Dacia (more or less modern-day Romania) in marvellous detail, from the building of forts to the launching of catapults.
The higher sections of the column are difficult to discern today, but would have been easily viewed by the ancients from galleries that used to stand nearby. (Plaster casts of the reliefs are now on display at the Museo della Civiltà Romana in EUR). At the top of the column is a bronze statue of St Peter, added in 1587 by Pope Sixtus V to replace the original one of Trajan (now lost). So beloved by the Roman people was Trajan that, when he died in AD 117, his funerary urn was placed in a chamber at the column base (covered with scaffolding as this guide went to press); this made him and his wife, Plotina, the only Romans whose remains were allowed to be placed inside the city's boundary. The height of the column, 38m (125ft), is believed to mark the elevation of that part of the Quirinal hill that extended into this area before it was cleared away to make room for Trajan's forum.
The Temple of Trajan, mentioned by ancient sources, was also around here, although the exact location is unknown. The rectangular foundation to the south of Trajan's column, where several imposing granite columns still stand, was the basilica Ulpia, an administrative building. Part of the floor of the basilica is now visible at the gallery space recently acquired and restored by Alda Fendi, of fashion fame (Foro Traiano 1, 06 679 2597, www.fondazionealdafendi-esperimenti.it, open for exhibitions only). To the west, under the walls that support via dei Fori Imperiali, are the remains of one of the libraries that also formed part of Trajan's forum.
The most distinctive feature of the forum complex is the multistorey brick crescent to the south-east of the basilica Ulpia. This great hemicycle, forming part of the Mercati di Traiano(Trajan's Markets), was built in AD 107, in part to shore up the slope of the Quirinal hill. Some scholars now argue that it was more of an administrative than a commercial space. When possible, the best way to appreciate its state of preservation is to visit the interior (as this guide went to press, restoration work meant that only the lower site was open, although the markets themselves were due to reopen at some point in 2007). Entering from via IV Novembre, the first room is the Great Hall, a large space possibly used for the corn dole in antiquity.
To the south of the Great Hall are the open-air terraces at the top of the great hemicycle, offering spectacular views across to the Capitoline and Foro romano. To the east of the Great Hall, stairs lead down to the so-called via Biberatica, an ancient street flanked by well-preserved shops. The shops here were probably tabernae (bars), hence the name 'Biberatica' (bibere is Latin for 'to drink'). More stairs lead down through the various layers of the great hemicycle, where most of the 150 shops or offices are still in perfect condition, many with doorjambs still showing the grooves where shutters slid into place when the working day was over. South of the hemicycle, the structure with a loggia with five large arches is the 15th-century Casa dei Cavalieri di Rodi (House of the Knights of Rhodes); its somewhat Venetian look is due to having been built by Venetian Pope Paul II. The slightly leaning tower beyond the hemicycle is the 13th-century Torre delle Milizie.