Why are some window bars curved at the bottom

 

Have you ever walked past an old apartment building and noticed window bars that bulge outward at the bottom?

At first glance, they might look like a decorative design choice — almost as if the metal bars have a little “belly.” But these curved window grilles actually have a surprisingly practical purpose that dates back centuries.

Known in some places as potbelly bars or belly grilles, these unusual window guards combine security, comfort, and functionality in one clever design.

More Than Just Decoration

Traditional window bars were originally installed to help