Underwater Tunnel (Submerged Cliff Tunnel)

A dark, narrowing submerged tunnel carved into coastal cliffs by a submarine. Cold, black water and thick marine vegetation fill the passage and snag survivors; jagged rock ceilings trap tiny air pockets—mere inches across—that Indy smashes into for vital breaths as currents rip him from the sub. The tunnel enforces total isolation, near-zero visibility, and constant drowning risk, turning escape into a suffocating gauntlet of blind survival.