After walking through the Garden of Tsar Simeon, we reached the Roman Forum. This partially excavated area is the remains of the hub of Roman Plovdiv, containing the main high street and a small arena called the Odeon (which has been rebuilt). A few of the original stone pillars marking the entrance to the forum have been re-erected, giving a glimpse into what this bustling marketplace once looked like.
Across the road, we came across an active excavation and conservation site, where we had a decent view from the road of archaeologists carefully revealing the remains of detailed mosaics. Apparently these are the remains of the Bishop Basilica of Philippopolis, also known as the Great Basilica. This was the largest early-Christian temple discovered in Bulgaria.