Building a curved architectural arch over a window seat frames the outdoor view like a living piece of artwork. Frame the front of a recessed window bay with a smooth drywall archway, painting the interior alcove a subtle contrasting shade to highlight its curved silhouette. Build a low-profile bench inside the arch, fitted with a custom tufted cushion that follows the contour of the space. Hang floor-length velvet or heavy linen drapery along the outer arch frame, allowing the nook to be fully closed off for privacy or cozy reading sessions. This architectural detail adds dramatic elegance and custom charm to bedrooms and living rooms.