The stand of play (as at March 2007) on the lava caves tube of Rwanda. Replaces volume 11 and 15 of this series. Includes the new longest cave of Rwanda (Ubuvumo Bwibihonga, at 4,530 m of length). Describes more than 72 caves with a passage length of over 25 km. Bi-lingual English/French with a German abstract.
 "The Caves of Rwanda / Les Grottes du Rwanda. 2nd Edition BHB Volume 23 Special Order")
