The Old Graveyard is a special cultural building first given as a reward during the 2013 Halloween Event.
The Old Graveyard provides happiness, and when it is polished, its output of happiness is doubled for 12 hours.
The Old Graveyard can be upgraded with a Graveyard Upgrade Kit item. To upgrade your Old Graveyard, use the Graveyard Upgrade item on the Old Graveyard that is already situated in your city. Its upgraded version will then be placed in your inventory, and the original Old Graveyard will disappear from your city (note that the upgraded building will be from your current era, even if the old one was from one of the earlier ages).
Graveyards: