Descending 70 feet into the World Trade Center’s bedrock foundations, the 9/11 Museum spans 110,000 square feet of gallery space. Visitors enter past two 80-foot steel "Tridents" before descending alongside the "Survivors' Stairs"—the final escape route for hundreds—and the massive slurry wall. Among the remnants, travelers encounter bent "Impact Steel" from collision zones and the crushed Ladder 3 fire truck, honoring first responders. Inside, personal memory meets global history. The In Memoriam gallery honors the 2,983 victims through portrait walls, audio memories, and keepsakes. Next door, historical exhibits detail the day minute-by-minute using news footage, air traffic transcripts, and personal artifacts, while examining the post-9/11 security landscape and international legacy that shapes our modern world.