蓮花山觀音洞是海南的一處地質奇觀，它的形成、發展、演變有著漫長的歷史。距今3.5億年前，石炭紀時代海南地區經歷了漫長的海相沉積，形成沉積的碳酸鹽巖地層，為巖溶洞穴的形成和發育提供了很好的物質基礎。約2億年時，巖漿侵入碳酸鹽巖地層，在侵入體的熱力作用下發生變質作用成為大理巖。隨后地殼抬升成為陸地，巖層經受了多次構造變動，形成眾多的斷層、節理、裂隙，為有溶蝕能力的水流提供了流動的路徑。在地下水溶蝕作用下，不斷地開拓流路，擴大通道，漫漫形成洞道，經過漫長歲月（約200萬年），地下水位下降，形成如今的觀音洞洞穴。

觀音洞洞內結構非常奇特，整個洞道長達2000多米，目前可游覽洞道有600多米，觀音洞在水流侵蝕和溶蝕過程中遺留下來的各種遺跡，用地理學家徐霞客描述洞的“曲、折、勾、連”來形容觀音洞非常合適。洞內有洞穴溶蝕形態、馬牙狀鐘乳石、吊巖、巖柱、等地質遺跡，具有其特有的科研價值和科普意義。洞壁上因礦物質沉淀形成的各種彩色斑斕的天然圖案，龍飛鳳舞，千奇百怪，極具特色。在洞內燈光映襯下，顯得既神秘又驚奇。其中一幅“慈母抱兒”圖案惟妙惟肖，堪稱世界一奇，仿佛是傳說中的送子觀音下凡，也具有很高的審美和觀賞價值。

Introduction to Guanyin Cave

Lotus Mountain Guanyin Cave is a geological wonder in Hainan, and its formation, development and evolution have a long history. 350 million years ago, Hainan experienced a long period of marine sedimentation in the Carboniferous period, forming sedimentary carbonate strata, which provided a good material basis for the formation and development of karst caves.About 200 million years ago, magma intruded into the carbonate strata, and metamorphism occurred under the thermal action of the intrusive body and became marble.Subsequently, the earth's crust was uplifted to become land, and the rock strata underwent many tectonic changes, forming numerous faults, joints, and fissures, providing a path for the flow of water with dissolution ability.Under the effect of groundwater dissolution, the flow paths were continuously opened up and the channels were expanded, and the cave passage was slowly formed. After a long period of time (about 2 million years), the groundwater level dropped, forming the current Guanyin Cave.

The structure of the cave is very peculiar, with the entire cave path being more than 2,000 meters long and the current tourable cave path being more than 600 meters. The various relics left behind in the process of water erosion and dissolution in Guanyin Cave are described by geographer Xu Xiake as of "bending, folding, hooking and connecting". Inside the cave, there are geological relics such as cave dissolution formations, horse-tooth-like stalactites, hanging rocks, rock pillars and so on, which have their unique scientific research value and scientific popularization significance. The various, colorful, splendid and vivid natural patterns formed on the walls of the cave due to mineral precipitation are highly distinctive. Reflected by the light inside the cave, they look both mysterious and wondrous. One of the patterns is “an affectionate mother holding her child”, which is a wonder of the world, as if it is the legendary Songzi Guanyin coming down to earth. It also has a high aesthetic and ornamental value.