A dark brown, grid-marked activity board is affixed vertically to a textured, light beige wall in the city of Sliven, Bulgaria

A dark brown, grid-marked activity board is affixed vertically to a textured, light beige wall in the city of Sliven, Bulgaria. A metal clip is attached to the top edge of the board. The board displays various manipulative objects arranged in five horizontal rows: * **Row 1 (Top):** A translucent light blue conical object rests on a dark green L-shaped bracket. To its right, two additional dark green L-shaped brackets are mounted side-by-side, appearing empty. * **Row 2:** A gray cylindrical object is horizontally positioned on a dark green L-shaped bracket. To its right, a small pink spherical object is contained within a dark brown U-shaped channel. * **Row 3:** A circular silver object with a blue cylindrical insert is mounted on the left. Adjacent to it, a vertical silver rod protrudes from a wooden block, which appears to house a spherical component. Further right, a rectangular dark green plastic piece with visible adhesive residue is attached. * **Row 4:** A silver rectangular block or bracket is mounted on the left. To its right, a light blue cylindrical roller with a silver axle is affixed horizontally. * **Row 5 (Bottom):** A small dark green rectangular bracket is positioned above a gray block securing a horizontal silver rod on the left. In the center, a multi-part light blue plastic mechanism resembling a clamp or hinge is fastened by a dark screw. On the far right, a silver metallic bolt with an attached hexagonal nut is mounted horizontally.