Ansel River (Elden Ring)

I got to the location through the elevator in the Laurnia region (there is a giant guarding the entrance), there are insects, a centipede from the ceiling and the boss Godzilla, I decided to kill him in his shorts and killed him, satisfied, but not quite, so who passed, how to get to other areas this location, there are areas on the map but you can’t get into them ..