I don't know how to post pictures but If you need me to figure it out I will read how to do it but I did take a screen shot. the coords are X= -619 Y= 24.5 Z=2239
I don't want to be accused of greifing but I was down in a natural cave when I found it. It appears to have a mushroom farm above it as well. I filled in my whole with cobble and left it.
According to the old post, mob traps are allowed but they can not be above ground. Above ground mob traps looks ugly, in almost everyones opinion.