While walking around Old Diriyah one day, we came across an open gate just like this (but without the sign, and very unusual looking) and were trying to look in when a man came out and invited us inside. It seemed to be some kind of place for social gatherings, and preparations were under way for a party that night. It looks like the property was also being updated into a nicer facility; I can see the building that we visited on the sign, just in a prettier setting.

When it rains, it pours in Riyadh, posted earlier: