You may have seen this screenshot of Bresha Ruins with a gigantic robotic hand stretching out of a pit before. It belongs to Atlas, a Square Enix representative explained. Atlas was the main enemy at the end of the Final Fantasy XIII-2 demo. Players either had the option of finding a way to control Atlas or fighting him head on, which led to a game over screen in the case of the demo.
How Atlas can be in New Bodhum and Bresha Ruins at the same time is a bit of a mystery, but there are things happening between dimensions. Crossing through dimensions and reality is a theme in Final Fantasy XIII-2.
After the events in Final Fantasy XIII, Lake Bresha thawed and people populated the area. Bresha Ruins is a home to many researchers who Noel and Serah will meet. The area has a town to check out and a water dungeon to explore.
Final Fantasy XIII-2 comes out in Japan this December and is slated for a January release in North America.