A woman prays at the African Burial Ground Memorial Site on Oct. 3, 2003. The caskets seen above were buried the next day and are now interred as part of the memorial to Africans and their descendants buried in Manhattan in the late 1600s and 1700s.

NYt / Suzanne DeChillo

NEW YORK — As we celebrate Martin Luther King’s birthday, on the eve of Black History Month, now is an excellent time to visit a serene new memorial to thousands of enslaved and free Africans and their descendants who were buried in Manhattan more than 200 years ago.

The dead, who were mostly forgotten over the centuries as New York City grew and a landfill and buildings covered their graves, now are commemorated in the African Burial Ground National Monument, tucked amid a tangle of government buildings, where office workers scurry through the streets.

About 15,000 Africans and their descendants were buried here in the late 1600s and 1700s in what was then rural land, estimates the National Park Service, which administers the memorial. The 6.5-acre burial ground was outside the boundaries of the New Amsterdam settlement, which later became New York, where slaves and free blacks were banned by whites from churchyard burial.

The memorial, which opened in October with speeches and spirituals, dignitaries and poets, has been a long time coming.

The human remains were discovered in 1991 during excavation for the expansion of a federal office building in Lower Manhattan. The African-American community, politicians and scholars plunged into a debate about preserving the site. Eventually, construction was halted and the remains of the 419 men, women and children were disinterred, documented and reburied, with the Washington, D.C.-based Howard University conducting intensive research. The African Burial Ground memorial was created on what is now a grassy plot of land, not much bigger than a suburban yard, on a street corner amid the warren of office buildings.

For a visitor, the African Burial Ground is an incongruous and thought-provoking place, a tiny sacred space in the heart of what has become some of the most expensive real estate in the world. Amid the bustle of Manhattan, it quietly sheds light on the history of slavery in New York and the men, women and children who were buried here.

The outdoor memorial, constructed of gray and black stone from Africa and America, sits on the grassy lawn. Visitors can walk through its ancestral chamber, a peak-roofed, 24-foot-tall tentlike structure of dark polished stone that’s designed to evoke both a slave ship that carried people from Africa to the New World and the soaring African spirit.

“The tragedy was that for so many years, for centuries, people passing by this site did not know about the sacrifices they had made,” Rodney Leon, designer of the memorial, told The Associated Press upon its opening. “Now we have an opportunity to right some of the wrongs of the past.”

Beside the ancestral chamber, a stone ramp spirals down to a small circular plaza, its walls lined with religious symbols from Africa and beyond. On the stone floor, a world map that focuses on Africa is inscribed on the stone floor, as are testaments to the dead who were found here: “Burial 96 — Young man between 16 and 18,” reads one inscription.

The unnamed youth was among the 419 people whose remains were found at this site, many wrapped in cloth shrouds and buried in wooden coffins. The dead and the artifacts found with them — beads, coins, clay pipes and more — have been studied and re-interred at the memorial site with seven grassy mounds on the lawn marking their final resting place. The remains of thousands of others still lie under surrounding buildings, sidewalks and streets in what is the largest known Colonial-era African cemetery in the United States.

On a sunny afternoon last fall, a park ranger stood at the entrance to the African Burial Ground. She handed out brochures and politely asked visitors not to eat or drink in respect for the dead. A half-dozen visitors who had come chattering off the adjacent sidewalk quickly quieted down. They slowly walked down the ramp or through the peak-roofed ancestral chamber where their whispers echoed. And they stood in silence to read words of remembrance engraved on its outside wall:

For all those who were lost

For all those who were

stolen

For all those who were left

behind

For all those who were not

forgotten.If you go

WHERE: The African Burial Ground National Monument is in Lower Manhattan just north of City Hall. The visitor center is at 290 Broadway; the outdoor memorial is on another side of the building, at Duane and Elk streets. It’s easily reached by public transport, including several subway lines; the Brooklyn Bridge/City Hall subway station is about a block away.

HOURS: The outdoor memorial is open daily from 9 a.m. to 5 p.m. There is no admission charge. The visitor center is also free but is open only on weekdays since it’s within a federal office building. (Visitors must go through airport-like security screening to enter since the visitor center is within a federal building.)

MORE INFORMATION:

•African Burial Ground National Monument: (212) 637-2019 or www.nps.gov/afbg/.

•There are links to extensive reports on the history and archaeology of the site at www.nps.gov/afbg/historyculture/.

•The Schomburg Center for Research in Black Culture, a New York-based institute that focuses on the African diaspora, worked for years to get the African Burial Ground memorial established; it has a commemorative Web site at www.nypl.org/research/sc/afb/shell.html.