As of 2015, the Sudokwon SLC Landfill in South Korea is currently the world's largest active, purpose-built landfill. The world's largest collection of garbage is the so-called great pacific garbage patch located in the North Pacific.
Korea's SLC landfill is an active waste disposal site as well as a massive energy generator and a tourist attraction. It services the Seoul metropolitan area. Mexico City's Bordo Poniente landfill is no longer receiving garbage, but until its closure in 2012, it rivaled the SLC, as it had the broadest surface area of any active landfill in the world, if somewhat less volume overall. For many years, the Staten Island landfill of New York City held the title of world's largest garbage dump, until it finally closed in 2001.
The great pacific garbage patch is an enormous area in the Pacific ocean containing a high volume of plastic. Unlike the landfills listed above, the oceanic garbage patch was not purpose-built to hold trash. Garbage collects there due to ocean currents. Most of the trash in the area is microscopic, or nearly so, making the garbage nearly invisible to boats passing through.