Abîme
Encyclopedia
An abîme is the geographical term for a vertical shaft in karst
terrain that may be very deep and usually opens into a network of subterranean passages.
Reference:
KARST
Kilometer-square Area Radio Synthesis Telescope is a Chinese telescope project to which FAST is a forerunner. KARST is a set of large spherical reflectors on karst landforms, which are bowlshaped limestone sinkholes named after the Kras region in Slovenia and Northern Italy. It will consist of...
terrain that may be very deep and usually opens into a network of subterranean passages.
Reference: