In 1959 prior to the construction of Aswan dam, UNESCO appealed to governments and archaeologists to help save historic sites that would be flooded by the lake the dam created. There was a concerted effort to save as much as they could
Polish archaeologist,Professor Kazimierz Michałowski’s team uncovered a buried Nubian Christian cathedral. Conservators from the National Museum in Warsaw along with the professor’s team managed to detach numerous walls, saving 150 paintings (tempura painted on dry mud plaster, called the Faras frescoes) as well as other artifacts from the remains of the buildings surrounding the church.
As previously agreed, the findings were divided between Poland and Sudan. In 2014 the National Museum of Warsaw reopened the Faras gallery, now designed to evoke the look and feel of the church the artefacts were from.
This google culture online exhibit explains the story and shows several images as well as a few videos. For more information, check out the Faras gallery website.
(image) National Museum of Warsaw Faras Gallery - St Anne fragment
I've seen some readers complain in the past about the number of science fiction books that uncover previous societies. What these readers fail to consider is the fact that all societies - unless you're talking about a new colony on a world without any sort of previous intelligent species - is built on the ruins of the past, often quite literally. Many important European cities have layers and layers of older cities beneath them. So it makes sense for characters in books to stumble across ruins, depending on the circumstances of the story. if nothing else, it shows that the world/universe has a history.