From the halls of Montezuma to the streets of Indianapolis, the U.S. Marine Corps is about to descend upon central Indiana.A force of about 2,300 Marines will use Indianapolis for urban combat training for two weeks, beginning June 4, 6News' Jack Rinehart reported.The Indiana State Fairgrounds is one of many landing zones in which Marines will jump out of helicopters to fight mock battles.The city offered 26 sites, many of them parks, identified as realistic urban training zones.The only round shot Tuesday at Douglas Park was on the golf course by military veterans who staged at the first tee while awaiting the Marine invasion."That would be beautiful. People would be out here looking at them getting down," said James Johnson. "They're supposed to get down. They're Marines."The Marines will land for two weeks of situational training. The expeditionary force of 2,300 troops will fire weapons, conduct patrols and react to ambushes in an unfamiliar urban environment."I think it's very good training for them. Actually, city fighting, urban fighting is really the most dangerous type of fighting there is," said Indianapolis Mayor Greg Ballard, a former Marine. "When you bang down a door you never really know what's behind there."The city surrendered several public sites, many of them city parks, where the Marines plan to land helicopters and deploy troops.In addition to war, the military plans to wage a public relations campaign to let people know what's coming, something that may be needed to keep the public from fearing the worst."I think (they should tell the public) so people aren't alarmed that they would see people in the park in uniform dropping out of airplanes," said resident Cathy Habeggar.The Marines will conduct training in Indianapolis, Columbus, Seymour, Hope, North Vernon, Greensburg and Camp Atterbury.From Afghanistan to Iraq, to Bush Stadium, Hoosiers and Marines will both be out of the comfort zones in hopes of a strong national defense. Police dispatchers will be alerted in advance to where the Marines will be operating."People will always like having Marines around. They're good people," Ballard said.Training is expected to finish on June 19.