Firstly, we will need four pallets, a drill, nails, corner braces, a leveler, and wire mesh. We will arrange the four pallets in a way that forms a square.

Next, we will level the pallets using a leveler to ensure the structure is properly aligned. This will prevent any misalignment in the overall structure. Once the pallets are leveled, we will join them together using corner braces, nails, and the drill. Two corner braces per corner and four nails per corner brace will be sufficient for this purpose.

Proceeding further, we will place a wire mesh at the bottom of our raised bed. This will allow water to flow through, preventing waterlogging. We will secure the mesh using nails on the inner lower part of the raised bed.

Next, we will take an insulator (preferably, like the one in the picture) with dimensions that fit inside the structure, and we will place it, securing it with staples and covering the entire interior of the structure. This way, we will be able to fill the raised bed with soil and then plant our photosynthetic organisms of interest.