洞どう門もん

noun

cave entrance; tunnel

Refers to the opening of a cave or a tunnel-like passage through rock. Often used for natural cave mouths or man-made rock tunnels.

• その洞どう門もんは岩いわ山やまをくりぬいて作つくられた。

  The tunnel was carved through the rocky mountain.

• 鍾しょう乳にゅう洞どうの洞どう門もんから冷つめたい風かぜが吹ふき出だしていた。

  Cold air was blowing out from the cave entrance.