You’ve probably seen them without giving it much thought—metal window grills with a strange little curve or outward bulge at the bottom. It might look decorative, or even accidental, but this unique shape actually has a powerful and practical purpose.

These curved-bottom window grills are most often found in older cities or neighborhoods with apartment buildings and tightly packed homes. And while they do add a bit of architectural flair, their real function is rooted in kindness and everyday life.

That extra curved space? It was designed as a makeshift garden.

In crowded urban settings where outdoor space is scarce, residents used that curved portion to place flower pots, herb planters, or even small vegetable trays. The curve provides just enough room for sunlight to hit the plants without taking up precious space inside. Over time, this feature became a beloved and practical part of the design, especially in places where green space was hard to come by.

But there’s more—it also served as a place for birds to perch, and even a spot where people would leave out small dishes of water during hot days for strays or wildlife.

So next time you spot a window grill with that curious curve at the bottom, know this: it’s not just metalwork—it’s a small gesture of beauty, resilience, and care in the middle of a concrete world.