Cave in Martinique

[adcliff]

Me again, couldn't see this on any other threads.
I was in a cave in Martinique (I think) that was very large. Down one of the tunnels there was a symbol on the floor that resembled a half sun with rays coming off it and what looked like a trap door in the wall. I stood on it and the use quick icon appeared, but I guess I'm missing some item to allow me to use it.

 

[P2000]

search the cave for the key. it is on a table with barrels in the room. First talk with someone in the jungle or the cave entrance and ask about the tounges of locals.