Mysterious Area

Below is Natlan, above is Snezhnaya. When I went to Snezhnaya in the main story, it suddenly became 'Let's go to Snezhnaya!' So I wonder if this area was part of a sub-story... 🤔 I've been progressing through the main story in focused mode. Speaking of mysterious areas, there was one above Mondstadt too. It seems I need to increase the exploration rate in both areas for the returnee event, but I don't think I'll make it in time 😂 The period is too short. It takes time just to advance the main story to the latest part for returnees, so I wish they'd think a bit more. Still, this mysterious area has four Seven Statues of the Seven. Is it an important area... I'm curious. ｡oஇ