CAMP HUMPHREYS, South Korea -- Once a bustling U.S. Army post in the middle of one of the world's largest cities, much of Yongsan Garrison now resembles a ghost town.While many Yongsan buildings sit abandoned next to blocked roads, the surrounding streets of Seoul outside its security gates pulse with life.Both the headquarters for 8th Army and U.S. Forces Korea and many other organizations have packed up and left for Camp Humphreys, located about 50 miles to the south.The 2nd Infantry Division will also move here from Area I, a collection of U.S. bases in between Seoul and the demarcation zone, as the Army changes its posture on the Korean Peninsula amid an emerging outlook on peace.Part of the U.S. Defense Department's largest peacetime relocation program, Humphreys has slowly become the U.S. Army's main hub in South Korea. The city of Daegu, which is another 100 miles further south, is the other hub.Even with fewer Soldiers near the DMZ, leaders believe the consolidation will actually improve readiness."It certainly helps us be ready and project power," said Col. Scott Mueller, the garrison commander at Humphreys. "This gives us an opportunity to be able to centralize functions and then be a launching platform should the need arrive."SMALL CITYHumphreys has transformed into a small city to make room for personnel and equipment trickling in from several camps in Seoul and north of the capital city. At almost three times its original size, it is now the largest U.S. military base overseas.Enough dirt to fill Yankee Stadium 29 times over was trucked in to provide the foundation for much of the revamped Army post. Nearly 700 new construction projects have already been built, including the newest post exchange and commissary, housing, medical facilities and schools.In the past few years, the post's population has ballooned from about 6,000 to 28,000 Soldiers, family members, civilians, contractors, and South Korean army soldiers. By 2020, when the transfers should be complete, there will be about 42,000 personnel on post."It's been quite an enterprise to make this happen," Mueller said.Consolidation efforts began in 2004 when the U.S. and South Korean governments agreed to relocate Soldiers to Humphreys while still providing them access to training sites north of Seoul.The Humphreys project costs about $10.7 billion -- roughly 90 percent of which is being paid by the Korean government.Many of the sites left by Soldiers will be returned to South Korea's Ministry of National Defense or local governments. In Yongsan, for instance, there are plans to eventually construct a public park with a lake.There is also cost savings associated with the U.S. Army having most of its facilities consolidated in one location. At Yongsan and other sites, this means less overhead resources required for schools, commissaries, security or other garrison services."We've reduced manpower requirements because it's all consolidated down there at Humphreys," said Paul Hubbard, the base closure team lead for Yongsan.ACCOMPANIED TOURFor those who live at Humphreys, they say the post has all the amenities they need and plenty of places to explore outside the gates.Capt. Terrence Strahan decided to do his tour accompanied with his wife, Kendra. While Soldiers can do one-year assignments alone, those accompanied with family members must stay for two years.During their tour, both have sightseen around the country, taken kimchi cooking classes, and attended a Korean baseball game, among other activities."It's been a great adventure, seeing the different culture and being able to travel around the country," said Strahan, a company commander in 2nd Combat Aviation Brigade's 4th Attack Reconnaissance Battalion.On any given day, the airfield at Humphreys is buzzing with activity from helicopters and other aircraft. As an Apache helicopter pilot himself, Strahan said the semi-deployed environment also offers realistic training to him and his unit.Kendra, a licensed practitioner nurse by trade, said she has enjoyed her time being fulfilled by the opportunities to volunteer. She teaches classes at the American Red Cross on post and assists in evacuation exercises and even at a local orphanage.After seeing her husband deploy two times before to Iraq and Afghanistan, she jumped at the chance to go to Korea and support him."It was so hard being away from him," she said. "It's a long time to be away, so if you can be here with them, be here with them."Mueller described South Korea as a very safe country. His three boys will often travel outside the post, hop on a bus and head to the nearby city of Pyeongtaek and even Seoul.His family has visited some of the country's beaches and skied in its mountains. They also went to this year's Winter Olympics, which were hosted a few hours away."Quite frankly, if the Army hadn't put me here I'm not sure if I would have ever seen this part of the world," the colonel said.While Humphreys boasts several fitness centers, pools and other recreation activities, and a large PX "with just about everything in the Army and Air Force Exchange Service inventory," Mueller said it would be a shame for a Soldier not to venture off post."You really could spend your entire year or your two-year tour here in Korea and never leave the garrison, except to maybe go train," he said. "To me, that would be a waste of a good opportunity. I tell the Soldiers to get out, to see Korea and experience the culture."END OF AN ERAMeanwhile at Yongsan, the Army has seen a steady reduction in its once large footprint.At one time, the U.S. Army had occupied about 1,300 buildings in Yongsan. A small residual garrison that will stay there will eventually control just 38 buildings. Most of the structures will either be used by the Koreans or demolished.Some of them date back to the Japanese occupation in the early 1900s. Those deemed to have historic value may be saved as part of a joint venture with the War Memorial of Korea across the street from the main post, Hubbard said."It's an honor to help facilitate that and to transfer the land back to them, so they can participate in a part of that history," he said. "A lot of Koreans have never even set foot on this soil."The moves are also bittersweet for Hubbard, who has spent 13 years in Korea as both a Soldier and civilian. For two years, he served as a flight medic at the Brian Allgood Army Community Hospital. That hospital is set to close as a new one with the same name prepares to open at Humphreys in late 2019.Many other structures are now vacant. Inside an old building that housed 8th Army's Headquarters and Headquarters Battalion, offices sit empty except for a few chairs and desks. Cobwebs float in the hallways and internet cables that once connected the building to the outside world now lay abandoned on worn-out floors.Because of its location within a megacity, Yongsan will likely be the most difficult camp the Army closes. Buildings need to be boarded up and fence lines moved in order to maintain security as parcels of land are handed back over."Until we get to closure, the consolidation has been our greatest challenge," Hubbard said. "We try to get rid of all the eyesores and block off areas as much as possible."Brand new buildings with upgraded equipment greet those who make the move down to Humphreys. The major headquarters buildings, for instance, have all the modern communications infrastructure needed to operate mission command systems and talk with counterparts in country or globally."These headquarters are wired for sound," Mueller said. "It's a big leap forward in terms of capability."Even as the garrison commander who has dealt with the transformation on a daily basis, Mueller said he is still amazed by the design and engineering efforts that went into creating such a large installation."This is no easy task. We've built a garrison essentially from the ground up," he said. "What we're sitting on here [now] was mostly rice paddies."