Guañape Islands
Peru
The Guañape Islands form an island group off the coast of northern Peru. The group consists of four islands: Isla Guañape Norte, Isla Guañape Sur, Islotes Cantores, and Islotes Los Leones. Off the southern coast of Peru, lie the Chincha, the Ballesta, the Lobos, the Asia, and the Guañape islands. These islands support breeding grounds for a variety of birds that feed on marine creatures. Over thousands of years, a 100-150 feet thick layer of guano accumulated. The primary producers of guano are white-breasted cormorants, grey pelicans, and white-headed gannets. It is estimated that around a million of these birds can live on one island and produce over 1,000 tonnes of guano annually.
Data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).