ATP International Series | International Monetary Fund | International Red Cross and Red Crescent Movement | ATP International Series Gold | International Space Station | Amnesty International | International Olympic Committee | BirdLife International | International Finance Corporation | International Organization for Standardization | International Telecommunication Union | International Criminal Court | One Day International | International Nonproprietary Name | International Labour Organization | International Civil Aviation Organization | International Boxing Federation | Toronto International Film Festival | International Atomic Energy Agency | International Maritime Organization | International Development Association | John F. Kennedy International Airport | Los Angeles International Airport | International Bank for Reconstruction and Development | International Court of Justice | International Fund for Agricultural Development | Rotary International | Marriott International | International Air Transport Association | Woodrow Wilson International Center for Scholars |
Tours are conducted by The Devil's Sinkhole Society, a local volunteer group that works in conjunction of Texas Parks and Wildlife Department and Bat Conservation International to facilitate visitor education and tours.