Kef Toghobeit Cave
Kef Toghobeit is a karst cave near the settlement of Bab Taza in Chefchaouen Province, Tanger-Tetouan-Al Hoceima, in northern Morocco. Currently known to be long and deep, it is the deepest cave in Morocco, and the third deepest cave in Africa.
Although Kef Toghobeit has been well-explored, its full extent is not yet known. Indeed, the karst topography of the Rif mountain range where the cave begins has barely been mapped - just 1000 caves are known in Morocco, and the geology would suggest that more than this exist.
Sierra de Tamaulipas
In the southeastern part of the Sierra in the municipality of Aldama, Tamaulipas is a limestone karst area in which many caves and cenotes (water-filled sinkholes) are found, including Zacatón which is the deepest sinkhole in the world with a depth of . In 1994, cave-diving pioneer Sheck Exley died attempting to dive to the bottom of Zacatón.