The entrance is located north north-east of Calis Point on Coron Island where some overhanging cliffs lead to small grottoes and holes. Once you've found the big cave entrance you have to find the narrow tunnel in the bottom leading to the cathedral cave.
This is an excellent diving excursion. You swim over coral covered fallen rocks to the big grotto entrance. The bottom of this main entrance is in a depth of 7 to 8m (23 to 26ft). Then you descend a small gap, which seems to have a dead end, down to a tunnel you have to swim through. Take note of the lobsters and cowries, swim in the direction of the light gleaming in front.
You exit at the bottom of a 20m (66ft) high chamber with about the same width. This cathedral is beautiful, especially when sun rays fall through a hole in the ceiling where a tree stood before it broke through and fell into the chamber. One third of the chamber is filled with water. You may get out of the water for a chat.
Beginners should have good nerves, no problems with agoraphobia and be accompanied by a native diving instructor. If the bottom is whirled up, it could be difficult to find out again. Who's afraid of this excursion may find interesting but not overwhelming corals and giant clams under the boat.