I still like
Savannah a lot as a nature name (and a place name;
Savannah's architecture is lovely!). Both
Savannah and Prairie are similar nature-theme names I'd consider. I think it's destined to be a little more dated than
Anna or
Hannah, but it's not in
Isabella levels of trendiness where it's forever going to be stuck in the 2000s and 2010s. It's a pretty name with a pretty image behind it. I prefer
Susannah and
Samantha to
Savannah, and I would think of those as sound-alikes before I'd think of
Anna and
Hannah.
Savannah is better than
Savanna to me, which just looks incomplete.