▁J ., ▁also ▁sculpt ures ▁and ▁a ▁cho ir ▁of ▁Johann ▁Joseph ▁Christian . ▁ ▁Natural ▁monuments ▁W ims ener ▁Hö h le ▁( W im sen ▁cave ), ▁a ▁since ▁ 1 4 4 7 ▁well - known ▁sea ▁cave ▁accessible ▁with ▁a ▁boat . ▁The ▁total ▁length ▁is ▁ 7 2 3 ▁meters , ▁but ▁only ▁ 2 6 3 ▁m ▁are ▁measured . ▁Zw ief alt endor fer ▁Trop f stein hö h le ▁( Z w ief alt endorf ▁stal act ite ▁cave ), ▁with ▁a ▁length ▁of ▁ 2 7 ▁meters ▁the ▁smallest ▁show ▁cave ▁in ▁Germany . ▁Zw ief alt endorf ▁is ▁sub site ▁of ▁R ied lingen . ▁A ach top f ▁( K essel bach ) ▁spr ings ▁in ▁the ▁valley ▁of ▁Dob el ▁valley , ▁similar ▁to ▁the ▁Bla ut opf ▁in ▁Bla ube uren . ▁He un eb urg ▁( Up fl am ör ) ▁is ▁a ▁C elt ic ▁r amp art ▁in ▁the ▁forest ▁near ▁Up fl am ör . ▁The ▁ 4 . 5 ▁hect are ▁site ▁was ▁settled ▁not ▁later ▁than ▁the ▁ 7 th ▁century ▁BC . ▁ ▁Schloss berg ▁Son der buch ▁with ▁Burg st all ▁Son der buch . ▁ ▁Reg ular ▁events ▁The ▁Nar ren z unft ▁Ra elle ▁e . ▁V . ▁oper ates ▁the ▁Sw ab ian - A lem ann ic ▁Fast n acht ▁in ▁place . ▁ ▁Econom y ▁and ▁infrastr ucture ▁ ▁Transport ▁Zw ief al ten ▁is ▁located ▁on