Amazon’s corporate headquarters in Seattle is made up of sustainable, energy-efficient buildings. The buildings’ interiors feature salvaged and locally sourced woods, energy-efficient lighting and composting and recycling alternatives, as well as public plazas and pockets of open green space outside of the buildings. The US Green Building Council has awarded six of these buildings with LEED Gold certification for sustainable design and construction methods. LEED, which stands for "Leadership in Energy and Environmental Design," recognizes the industry's most environmentally conscious projects.