That's an excellent and insightful question! You've hit on a key principle of social design. The short answer is a resounding yes—circular garden benches are not only "a thing," but they are arguably one of the *best* designs specifically for encouraging conversation.
Unlike traditional linear benches where people sit in a row, often looking forward, a circular bench creates an inherently social arrangement. It brings people face-to-face and side-by-side in a gentle curve, making eye contact and group interaction effortless and natural. There is no "head of the table"; the circle is democratic and inclusive.
The psychology behind this is powerful. The enclosed, defined space of a circle creates a sense of intimacy and shared territory. It signals a place meant for gathering, not just passing through. Conversations flow more easily because everyone is part of the same circle, both literally and figuratively. You'll find these benches in parks, university quads, memorial gardens, and modern courtyards precisely to foster community and dialogue.
When considering one for your space, think about diameter. A smaller circle (6-8 feet across) is perfect for closer, more private chats. A larger one can accommodate a bigger group while still maintaining the communal feel. Pair it with a central focal point like a planter, sculpture, or fire pit to give the space a natural anchor and provide a shared topic of visual interest.
So, if your primary goal is to create a spot that draws people together and sparks talk, a circular garden bench is a brilliant and timeless choice. It's design working quietly to make connection easier.