The Museum of History & Industry (MOHAI) is a history museum in the South Lake Union neighborhood of Seattle, Washington, United States. It is the largest private heritage organization in Washington state, maintaining a collection of nearly four million artifacts, photographs, and archival materials primarily focusing on Seattle and the greater Puget Sound region. A portion of this collection (roughly 2% at any given time) is on display in the museum's galleries at the historic Naval Reserve Armory in Lake Union Park. MOHAI's highly facilitated, hands-on field trip programs use authentic historic materials to promote teamwork, creativity, communication, visual literacy, critical thinking, observation, and problem-solving skills.