New Rome is guarded by the Roman campers of Camp Jupiter in order to be a refuge for Roman demigods, legacies, nature spirits, and minor gods. It is located somewhere along the Little Tiber and Romans must serve ten years in the legion to live and retire here. Currently, it is located in California of the Western United States in the Berkeley Hills.
The buildings are made of white marble with red tile roofs and include townhouses and shops (in addition to the domed senate house), a forum studded with statues and columns, and models of the Circus Maximus and the Coliseum. It provides housing and education for demigods and their families once their ten years with the legion are up. Just outside of the city is Temple Hill, with temples to many of the Roman gods. The city is a sacred 'safe zone' in the words of Frank Zhang; no weapons are allowed inside the Pomerian Line that defines its boundaries. This is guarded and enforced by Terminus, the statue god of boundaries.
The citizens of New Rome are almost all veterans of the legion, some of whom apparently have seats in the senate where they advise the current praetors in addition to forming a trained reserve which is seen fighting in defense of their city in the great battle that climaxes in The Son of Neptune.