An ice cave is any type of natural cave (most commonly lava tubes or limestone caves) that contains significant amounts of perennial (year-round) ice.
ɐn ˈaɪs kˈeɪv ɪz ˌɛni tˈaɪp ʌv nˈætʃɚɹəl kˈeɪv mˈoʊst kˈɑːmənli lˈɑːvə tˈuːbz ɔːɹ lˈaɪmstoʊn kˈeɪvz ðæt kəntˈeɪnz sɪɡnˈɪfɪkənt ɐmˈaʊnts ʌv pəɹˈɛnɪəl jˈɪɹˈaʊnd ˈaɪs.