After four years of extensive changes, Arlington National Cemetery has finished the expansion project that started in 2014 and will open the space for use in upcoming weeks.

The expansion, officially know as the Millennium Project, added 27 acres of land, 6,000 pre-dug graves and 16,000 niche wall burial spaces to the 154-year-old cemetery, which is slowly running out of room to honor and inter America’s military veterans.

The new section has room for traditional in-ground burials and also in-ground burials of veterans’ cremated remains.

The Millennium Project, the first expansion of the cemetery space in nearly 40 years, cost around $81.7 million. The expansion space was taken out of a recreation spot for a nearby military base, a construction staging area for the cemetery and National Park Service woodland, according to The Washington Post.

The expansion features a new system for saving space and efficiency, Army Col. Mike Peloquin, the cemetery’s director of engineering, said in the Post report.

Concrete boxes used for burials will be double stacked, with space for two caskets. The concrete containers will be about 18 inches under the ground surface, and spaced closely together.

According to Renea Yates, the deputy superintendent for cemetery administration, the expansion will add decades onto the life of the cemetery. However, continued expansion will still be needed as the cemetery continues to delay the inevitable day when there is no more room left for burials in the military cemetery.

Vice President Mike Pence places a flag at a gravesite in Section 60 during Flags In at Arlington National Cemetery, Arlington, Virginia, May 24, 2018. Pence also visited with Arlington National Cemetery and Old Guard leadership. (Elizabeth Fraser/Arlington National Cemetery)
Vice President Mike Pence places a flag at a gravesite in Section 60 during Flags In at Arlington National Cemetery, Arlington, Virginia, May 24, 2018. Pence also visited with Arlington National Cemetery and Old Guard leadership. (Elizabeth Fraser/Arlington National Cemetery)

Even with the new 27-acre expansion, the future of the cemetery is uncertain.

“Most veterans from the recent wars in Iraq, Afghanistan and the war on terror will not have the option to be buried” there, the cemetery wrote in a report in 2017, according to the Post.

Following the expansion, Arlington has about 100,000 spaces remaining.

The cemetery, considered to be the most famous in the country, honors more than 400,000 people buried there since 1864.

With an eye towards extending its life, the cemetery is looking at all options, even seeking public comment on whether the eligibility to be buried there should be made more restrictive. According to the 2017 report, the eligibility rules for burial in the cemetery have been changed 14 times in the last 150 years.

The cemetery is also planning another addition, one that will add 37 acres of land. The project, titled the “Southern Expansion,” will encompass the land where the old Navy Annex building was located before its demolition in 2013.

The project is expected to cost $274 million and be completed by 2025, extending the cemetery’s life into the 2050s.