Caves in Guyana

Are there any caves in Guyana? Very few it seems which is not too surprising given the lack of suitable geology.

There is one cave under Kaieteur Falls.

There are also a few caves in the Roraima area (see picture) including one called the Oil Bird Cave. I am not sure if all these are in Guyana.

Note: there seems to be several caves called Oil Bird Cave. Oil Birds live in colonies in caves in this part of the world.

Links
http://www.wilderness-explorers.com/guyvenez.htm
http://www.mathiaskessler.com/island-of-time-roraima/index.html