In the late 1770s, Christopher Gadsden was the imminent heir to his father’s fortune, a slave trade magnate, and the designer of the rattlesnake flag now flown by the ascendant American white supremacist movement. But in that time, he also completed Gadsden’s Wharf. The massive shipping complex became an infamous site where the human depravities of the slave trade were on full display as a bustling marketplace, giving over 840 feet of prime Charleston riverfront territory to ships stacked with enslaved Africans. Six ships could dock at once; on dry land, a thousand enslaved men, women, and children could meanwhile be held in wait to be sold or trafficked to parts unknown. Until recently, to many, the land’s history might also have been unknown. The ground on which an estimated 100,000 Africans were delivered, and its coast off which untold more were drowned, has been an overgrown lot in the shadows of a condo development remarkable only for its grim name, the Gadsden.

For decades, local politicians like Charleston mayor Joseph P. Riley Jr. have pushed for a structural acknowledgment of the city’s centrality to the slave trade and a memorial to those enslaved and killed. Major architectural figures, including the late Harry Cobb of Pei Cobb Freed & Partners and landscape artist Walter Hood, have devised plans, and representatives of local Gullah Geechee people have advised them. Yet politicians like Republican state representative Brian White have withheld promised funding. The South Carolina Heritage Act, signed into law in 2000 by Democratic governor Jim Hodges, makes illegal the removal or rededication of any public statues or areas named after a historic person or event (even as it calls the Civil War the “War Between the States”). Perversely, if the site of the former Gadsden’s Wharf were public land, a memorial like the one that now rises from the water’s edge wouldn’t be possible.

But rise it does, in the form of the new International African American Museum, an elegantly cantilevered, single volume building that embodies Cobb’s vision and serves as a culmination of his firm’s decade-plus-long collaboration with architect of record Moody Nolan. It seems to step out of the Atlantic and pause between the past and the future. Pale yellow brick lightens its monumental horizontality. The building’s ample glazing is cooled by clever louvers made of African sapele, which shade interior spaces from the sun but simultaneously allow for views of the Atlantic coast and the Charleston skyline. “We wanted to make this connection,” said PCF&P associate partner Matteo Milani, “because the story of the site is between the ocean and downtown Charleston.”

The museum’s interiors are almost entirely open. Visitors rise, courtesy of a stone stair, into an atrium. Next, exhibition designer Ralph Appelbaum moves them toward the ocean and through multimedia displays of the region’s history, as if to say, you can’t escape the past. Then come interactive galleries examining modern-day social justice movements, arguing that we can—and must—try. In order to make this a living history, the museum also includes a research center, supported by the Center for Family History, offering a bounty of primary sources and other archival documents so researchers and the public alike can learn about their personal histories.

What separates the IAAM from other worthy institutions, however, is the ground it sits on—or, rather, floats above. “The site is more important than the building itself,” said Milani. Just plunking down a building, however elegant its form, might compromise that importance, reburying the remains of the wharf. Instead, 18 columns, in two rows, lift the volume some 13 feet off the ground. Each column is clad in oystershell tabby, a mixture of equal parts lime, water, sand, oystershells, and ash. Historians have yet to definitively determine whether northwest Africans developed the material, but the building technique came with colonists to America in the late 1500s, where it became a distinctive part of Southern vernacular architecture, particularly the self-built homes of the enslaved. Today, the unmistakable suspension of shells lends symbolic heft to the columns, which taper in almost religious deference to the weight of the museum. Their shape fends off allusions to parking garages. Their strength keeps the building safe from floods—and also keeps the earth safe from the building. “This is sacred ground,” said Moody Nolan founder Curt Moody. The plan foregrounds its significance.

It also creates a plaza beneath the building itself, dedicated to public contemplation and organizing. Walter Hood and principal Paul Peters conceived a trio of risk-taking interventions for the plaza and its surroundings. To the north, the studio planted “hush harbors” within mazes of brick walls. These reference the secret gardens planted by enslaved Africans as havens away from their owners. Hood reimagines them in The African Ancestors Memorial Garden, a series of reflective spaces hosting native Lowcountry species like sweetgrass and cypress. Altogether, they outline the historic footprint of the large warehouse in which enslaved people were stored. “They establish this site as an authentic place of arrival,” Hood wrote in a statement. “The site’s hallowed ground and landscape spaces offer contemplation, celebration, and distraught memories.” This history is brought back to life with parallel walls of reflective black granite, between which cast-concrete figures of African people kneel.

Boldest of all the museum’s design interventions, however, is a fountain at the water’s edge. Here, at the eastern boundary of the former wharf, a tidal pool seems to join the Charleston Harbor. When the sun hits, the water casts light onto the museum. But when the tide goes out, the receding water reveals full-scale human figures carved out of concrete and oystershell pavers, in rows that recall the wicked stacking of enslaved people shown in the notorious 1787 Brookes diagram—a document of the horrors enacted by the slave ships Gadsden courted. Museum visitors will work out for themselves whether their witnessing of Hood’s creation revivifies the trauma of the slave trade or in some baptismal way might allow a healing from it. The project’s power might depend upon the idea that the two, at least today, can’t be untangled.

Yet there’s dignity in such difficulty. “We’ve been with this project for 15 years, and there were plenty of chances to give up,” Moody said. “But it was too important, for what it represents and where it is. There are only a few museums that occupy a place with these kinds of connections. The country would be poorly served to have never done this one, on this site.” Charleston, and this country, is well-served by the work.

Jesse Dorris is a writer based in New York City and hosts Polyglot, a radio show on WFMU.