ANY shelf turned on it's SIDE.... add long foam cover pad. ( or use one that fits from the patio ) add pillows and you have a lovely .... WINDOW SEAT . Colours and Choices of Pillows are yours. I would love to do this all in a Shabby Chic design.... Cool
Use a twin sheet folded long ways. Sew 5 sections to the size of pillowcases and slipped the pillows in. Leave each pillow compartment end open so the pillows can be removed and the cover can be washed.
Take 5 pillowcases, sew them together. Nothing special, just a straight line needed. Stuff with 5 pillows (you’ll probably want them on the flatter side, meaning you can go wild with the really cheap ones). BOOM. You’ve got a Nap Mat.