Where is the headquarters of the think-tank Atlantic Council (AC)?

The Atlantic Council (AC) is a US-based think-tank to promote constructive leadership and engagement in international affairs based on the central role of the Atlantic Community in meeting think tank. The headquarters of Atlantic Council (AC) is located at Washington DC, United States. It is in news because Manish Tewari, the Congress leader and former Union Minister, has been appointed as the senior fellow of US-based think tank Atlantic Council.