Marathon Oil Corporation is a United States-based oil and natural gas exploration and production company. Principal exploration activities are in the United States, Equatorial Guinea, Poland, Angola and Iraqi Kurdistan. Principal production activities are in the United States, the United Kingdom, Norway, and Equatorial Guinea. Within the United States, Marathon Oil has recently focused development efforts on liquids-rich shale plays, including the Bakken and Eagle Ford formations. Marathon Oil owns interests developing Athabasca oil sands (Canada) resources and in Waha Oil Company (Libya). Marathon's headquarters facility is the Marathon Oil Tower in Houston, Texas.