▁the ▁logging ▁area , ▁there ▁is ▁a ▁designated ▁wild life ▁reserve ▁where ▁de er , ▁water ▁buff al os , ▁wild ▁p igs , ▁b ats , ▁flying ▁fo xes ▁and ▁species ▁of ▁re pt iles ▁and ▁birds ▁can ▁be ▁found . ▁In ▁ 2 0 1 5 , ▁the ▁conservation ▁area ▁protect ing ▁the ▁mountain ' s ▁e cos ystem ▁was ▁upgrad ed ▁to ▁a ▁national ▁park . ▁ ▁Ex pl oration ▁of ▁the ▁cal der a ▁floor ▁ ▁Z ol ling er ▁( 1 8 4 7 ), ▁van ▁Rh eden ▁( 1 9 1 3 ) ▁and ▁W . ▁A . ▁Pet ro es chev sky ▁( 1 9 4 7 ) ▁could ▁only ▁observe ▁the ▁cal der a ▁floor ▁from ▁the ▁cr ater ▁rim . ▁In ▁ 2 0 1 3 , ▁a ▁German ▁research ▁team ▁( Ge ores earch ▁Vol can edo ▁Germany ) ▁for ▁the ▁first ▁time ▁carried ▁out ▁a ▁longer ▁expedition ▁into ▁this ▁cal der a , ▁about ▁ 1 3 0 0 ▁m ▁deep , ▁and ▁with ▁the ▁help ▁of ▁a ▁native ▁team ▁clim bed ▁down ▁the ▁southern ▁cal der a ▁wall , ▁reaching ▁the ▁cal der a ▁floor ▁while ▁experien cing ▁extreme ▁conditions . ▁A ▁German ▁ge os cient ist ▁in ▁the ▁team ▁was ▁the ▁first ▁European ▁woman ▁and ▁world wide ▁the ▁first ▁woman ▁to ▁conquer ▁the ▁inner ▁southern ▁wall ▁of ▁this ▁vol cano . ▁The ▁team ▁stayed ▁in ▁the ▁cal der a ▁for ▁nine ▁days . ▁People ▁had ▁reached ▁the ▁cal der a