There is still a bit more to go, so prepare and head back up the path, and follow it until you find a path to the light down a ladder. Turn around and go to the first room on your right. If you're looking for more help, our Dark Souls walkthrough and guide can help with all other areas of the game, including the dreadedTaurus Demon, Capra Demon, Ornstein and Smough bosses. To get to the Tomb of Miktrull, you'll have to head to the Crash Site.
Thankfully, nearly all the creatures in the Tomb of the Giants have very short aggro range, which means that if players do have a light source (or can see their glowing eyes in the dark) then they can be the first to attack or attempt evasive maneuvers.