As, the title mentions, it is New Rome, so they do not have much history. They are located in San Francisco, California in the Caldecott Tunnel. The legion, had been in a different location before, but in 1906, a major earthquake destroyed the camp, and was blamed on Frank Zhang's great-grandfather Shen Lun(a legacy of Poseidon). Later his name was cleared, and New Rome grudgingly, accepted Frank into the legion. They rebuilt New Rome and moved it to their current location and reside there now.
New Rome, is a safe place for all Roman demigods and their descendants after them. It has always been gaurded by the Roman campers of Camp Jupiter. It is where Roman demigods can live, go to college, get married, and start a new life. The entire thing is like a mini country.
The buildings all have red rile roofs and white marble walls. This also means the townhouses, the shops, and the Senate House, all have the same appearance. They are modeled after Circus Maximus and the Coliseum from Ancient Rome in Italy. It is two times as big as Camp Half-Blood, and has many temples to the Roman gods. Like Camp Halfblood, they provice education as well as training and housing.
No weapons are allowed inside the Pomerian Line, that defines the cities boundries. this law is enforced by the god Terminus. (See picture.) Citizens of New Rome, most all grow up to regular age. At Camp Half-Blood, they don't expect anybody to survive that long, but in New Rome they are almost all veterans of the legion, some of whom have all been praetors or in the Senate House at some point. They advise the current praetors, telling them what they would have done, and help train the younger demigods. In The Son of Neptune they help fight against the giant attack.