Civilization existed on the planet for over two billion years and it was therefore one of the most important archeological sites in the galaxy. Up until 2367, 947 archeological expeditions had been conducted, with 74 of them revealing findings of major importance, the first one 22,000 years prior and the last one within the 400 years before 2367. A significant number of these excavations had been conducted by Vulcans, though confined to the northeast of "the city".
The Taguans sealed off their planet to foreign visitors in the mid-23rd century, but the planet was still the focus of much interest. In 2367, the annual symposium of the Federation Archaeology Council was held in orbit of Tagus III on board the USS Enterprise-D. (TNG: "Qpid")
In the novel Q-Space, Q takes Captain Jean-Luc Picard in Tagus III's distant past to witness a prominent local ceremony of the era, Q noting that he enjoyed visiting that moment in his youth as it reflected how lower lifeforms were willing to risk everything and take chances to do something with their lives.