Cemetery, Graveyard, Necropolis, City of the Dead. Pretty much every fantasy city, town and village has such, and they have a great promise of adventure: Necromancers looking for bodies, haunts with unfinished business, buried treasures and even a whole unholy domain, especially at night time – as Necropolis and it's Dark Reliquary in Ptolus.
Some settlements or people may of course have different habits, some being grotesque: Burning the dead, on bonfire or a boat or ship, eating them, or living among them, like Cairn Lords in Beasts & Barbarians. This is very cool setting I've reviewed earlier – I haven't read Steel edition but it's the latest version right now.
In my opinion, Old graveyards look very beautiful and promise – even demand adventure. If you have a chance to visit an old graveyard with mausoleums, do so! My favourite place is Montmartre's cemetery in Paris, near Sacre Coeur. I'll add some photos below from the graveyard to give the picture – but I'm afraid many of my photos have disappeared during harddrive crashes and other problems.
One of my first terrain projects was a graveyard terrain, and they've seen their share of use. But my terrain is quite modest on todays standard, and if you want to create terrain of you own and desire loads of inspiration, you should head towards Pinterest: https://www.pinterest.com/search/pins/?q=rpg+graveyard+terrain
There's some really good Graveyard maps around. Black Scroll games has been fast growing to be my favourite mapmaker, and a while ago they published Cemetery set, wrecking my just-started project to make cemetery tiles of my own. Zovya's Autumn cemetery is a very cool one if you want an autumn one, and if you go down to crypts under remember that Heroic Maps' crypts are maybe the coolest looking pieces of small maps there is.