The topographical model of this Roman site told the story for this site and for most of the other small towns we visited in Portugal. The Romans favored hill tops for defensive reasons with access to water, often via an aqueduct. In a few cases the aqueducts had been refurbished in intervening years and some were still functioning.
The site at Conimbriga was only twenty percent excavated but it was impressive. The museum at the site with the artifacts found there was small but had a lot of artifacts of all types, scissors and phallic symbols. Yes, the Romans had scissors.
The mosaics and a beautiful Roman arch were impressive. The mosaics reminded me of those I saw at a Roman site in Sicily. A preserved and covered portico was beautiful. The site had a thick wall added later for defense purposes. There were settlements both inside and outside the wall.
Below is a link to the Conimbriga Roman Ruins Slideshow.