For the casual visitor, this site doesn't offer as much as the spectacular Kom el Dikka or the Catacombs of Kom el Shaqafa. The red granite column for which the site is named is admittedly massive -- 9m (30 ft.) around and 30m (100 ft.) tall -- but had nothing to do with the Roman General Pompey (who was killed here in 48 B.C.), and was erected in A.D. 293 for Diocletian. It used to stand in a large temple to Serapis and is now flanked by a pair of sphinxes from Heliopolis. There are some catacombs underneath that are worth the small fee that you'll need to pay the "guard" for a tour. The rest of the site is an unimpressive and rather bleak hillside.
It's an easy walk from here to the Catacombs of Kom el Shaqafa, and it's best to do them as a pair. If you're in a hurry, you can actually get a decent view of the column from the road before continuing on to the catacombs. To walk there, just turn right on leaving, and follow the edge of the dig to the first big street. The entrance to the catacombs will be on your left after about 100m (328 ft.).