The Cat Window Perch provides a comfortable and large surface for your cat to rest while enjoying the view or laying in the sun. Keeps cat off your precious furniture. Secures easily to your windowsill.
DIY Hanging Window Basket Cat Perch - Hymns and Verses
I love these simple cat climbing shelves posted over at Saucy Dwellings. They used Ikea Lack shelves with a custom made shelf that wraps around the corner and leads to a window shelf over the front door. Brilliant! *They don't look like "cat climbing shelves", they just look like a nice shelving display! ; )