We started the day at the Cryptoporticus, which is a little difficult to explain. The Forum was built into a hill and underneath there were lots of shops in a double arcade. Like a walk-out basement - the shops were underground at the back, but at ground level in the front. All of it is below ground level now.
You enter from the main square, through the Hôtel de Ville (the Town Hall), and go down down down some metal stairs and you find this wonderful underground arcade stretching a long way. The COG and I were the only people there, which was awesome. It's a three sided, U-shaped arcade, but there are some areas where it is deeper than just one shop on either side of the walk, so it's a little more complicated than that and a little more fun to wander around in.
Think for a moment about the continuity of this, what it means - today's central square is built where the Roman forum was, right over part of it. That just boggles my mind. So here's a couple of pictures:
Looking in one direction
And in another direction.