Is it safe to burn wood in a woodburning fireplace that has a capped natural gas line?

We just moved into a brand new home with a fireplace. The fireplace has a capped natural gas line that sticks out about 3 inches into the fireplace. It also has a shut off/on valve with a key on the outside of the fireplace. The fireplace also has an instruction booklet that states that it is a wood burning or a gas log fireplace. Is it safe to burn wood in the fireplace with the capped gas line? Also, I know this is probably a stupid question, but is there a standard direction in which the valve has to be turned to make sure that it is off? Thanks in advance for all your help!!