The Women In Military Service to America Memorial at Arlington National Cemetery in Virginia.
The structure was originally built as The Hemicycle, a new ceremonial entrance to Arlington National Cemetery constructed along with Memorial Drive from 1930 to 1932. But the financial problems of the Great Depression left it unfinished. By the late 1980s, it was overgrown with grass and run-down. Congress approved a women's military veteran memorial in 1985, and the memorial was finished in 1997.
This is more than a memorial; it's actually a small museum, with auditorium and gift shop, which explains the ever-changing role of women in military service. It also hosts the world's largest database of women veterans.