Scientists have discovered that a vast river network was occupied the sands of the western Sahara desert.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/massive-river-once-flowed-across-sahara-scientists-find-paleoriver-network-under-desert-sands
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/science-world-report
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-resources
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/rivers
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/africa
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/deserts
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/history
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/scientists