Some lie more than stand as such. These are known in the megalithic trade as "recumbents".

This is the "slaughter stone" close to both the clay oven and the main circle..  It has not yet been used for its stated purpose. Uses include a warm bed on a sunny day , a table to place pizzas and a window ledge framing the summer solstice on December 21st.

A recumbent slab at Stonehenge is also known as the slaughter stone , but it remains speculative as to whether bloody murder was ever committed here.

Recumbent stones are a feature of some circles , especially in Scotland. A number are bordered by a pair of tall "flankers" and in some cases this frames the setting moon. This opens up all sorts of social possibilities.

My stone came from a quarry about 5 miles up the road. It was the best of a bad bunch in a quarry that had been inexpertly blasted . I levered/hauled it onto the trailer and it cost me a slab of beer. The stone weighs about a ton and is nice and smooth. I  fantasise about acquiring a pair of flankers one day. They would need to be massive..