In a recent game, when I revealed antiquity sites, I was notified of one in my territory underneath a district I had already constructed. I was able to excavate this with an archaeologist. However, even playing with resource icons on, the district "covered up" the antiquity site, so I had no indication other than the notification for discovering a new strategic resource in my territory.
The terrain tooltip correctly listed the site, but it would be extremely tedious to hover over every district, wonder, and city center tile on the map looking for additional sites. Is there any other way to list all remaining sites?