911 Memorial Pool Inside the National September 11 Memorial
The 911 memorial pool inside the National September 11 Memorial sits within the footprints of the original Twin Towers in Lower Manhattan. The memorial features two large square pools, each approximately one acre in size, making them the largest human-made waterfalls in North America. The pools are set within a memorial plaza designed by architect Michael Arad and landscape architect Peter Walker, with the waterfall design by engineer Dan Cassidy. The memorial opened to the public on September 12, 2011, one day after the tenth anniversary of the attacks. The site is managed by the National September 11 Memorial & Museum, a nonprofit organization operating under a public-private partnership with the Port Authority of New York and New Jersey. For background on the Port Authority's role in the site's development, see its official overview at panynj.gov.
The 911 memorial pool inside the memorial complex is framed by bronze panels inscribed with the names of nearly 2,983 victims of the September 11, 2001 attacks and the February 26, 1993 World Trade Center bombing. The names are arranged according to an algorithm that groups people by their relationships and affiliations, a process developed by the engineering firm Snøhetta in collaboration with the memorial team. The pools are surrounded by more than 400 swamp white oak trees, creating a grove within the urban setting. The memorial plaza itself covers approximately 8 acres and was designed to accommodate high visitor volumes while maintaining a contemplative atmosphere. Visitor statistics are tracked by the memorial museum, which reported millions of annual visitors in its public reporting periods.
Inside the 911 Memorial Pool: Design, Waterfall, and Construction Details
Each 911 memorial pool inside the memorial occupies a square footprint measuring roughly 200 feet on each side. The pools are edged with a granite surround, and the water cascades down into a central void, creating a reflective surface that visitors can see from the surrounding plaza. The waterfalls are powered by pumps designed to operate continuously, with the water recycled within the system. The construction of the memorial pools was part of a broader rebuilding effort that included the new One World Trade Center, the transit hub, and other infrastructure. The memorial pools were built by a joint venture of Tishman Construction and Bovis Lend Lease, with the overall memorial design executed under the supervision of the Lower Manhattan Development Corporation.
Waterfall Engineering and Materials
The waterfalls at the 911 memorial pool inside the complex are engineered to produce a continuous sheet of water that falls into a square basin. The basins are lined with a specialized waterproof membrane and finished with granite to ensure durability and a reflective quality. The water is filtered and recirculated, reducing the need for continuous fresh water intake. The sound of the waterfalls is intentionally designed to create a buffer from the surrounding city noise. The memorial's construction materials, including the granite and bronze, were selected for their longevity and ability to withstand high visitor traffic and weather exposure. For a technical perspective on large-scale memorial engineering, see the structural engineering resources at asce.org.
Visiting the 911 Memorial Pool Inside the Museum Complex
Access to the 911 memorial pool inside the National September 11 Memorial is free and open to the public daily, with hours adjusted for seasonal changes and special events. Visitors enter through the memorial plaza, which is located at the World Trade Center site, accessible via the WTC Cortlandt subway station and multiple nearby transit connections. The memorial is operated in coordination with the 9/11 Museum, which is located below the memorial plaza and charges separate admission. The