I thought we could start a list of the elements that make Gothic novels, well, Gothic. I have started the list, and I would love for you to add elements to the comments. I'll revise the list and give credit where it is due as well.
I have divided the list up into sections as well.
Characters:
-- questionable, dark hero
-- heroine in danger (usually ages 18-25)
-- virgin heroine
-- hero with secrets
-- recluse
-- sick or dying matriarch or patriarch
-- evil stepmother or aunt or other older female figure
-- evil older male character (anti-hero, antagonist)
-- child in danger
-- old sea captain
-- heir or heiress in danger
-- orphaned heroine
-- heroine of lowly means turned governess
-- gypsies
-- old crones with "the sight"
-- witches
-- deceased wife or husband who still haunts the hero or heroine
-- kind male friend who helps the heroine but is not a love interest
-- childhood friend who wants to be love interest
-- "mad" woman or relative
-- the Other-- person who is not Anglo Saxon and thus appears mysterious or frightening
--"monstrous" person or deformed person
--disabled person who seems threatening (thinking of villains in wheelchairs etc).
-- servant girl who informs heroine of dangerous goings on
-- hero with a limp
-- idiot savant
-- angry peasants
-- mute child (or adult) with a secret
-- blind child or adult
-- vicar or priest who is not what he seems
-- vampires
-- evil servants colluding with their masters
-- cute, mysterious or clever cat (Thanks, Hannah. How could I have forgotten this one??)
-- lovable or courageous dog (And again, Hannah's contribution...)
-- child or adult who has second sight or vision (~Hannah)
-- secret benefactor
-- cruel school mistress or head of orphanage
-- missing person (childhood friend or sibling, often)
-- seductive lord or lady
Setting:
-- exotic locale
-- haunted ancestral home or mansion or castle
-- island
-- lighthouse
-- on the moors
-- old, abandoned church
-- old abbey
-- isolated home or cottage
-- in Cornwall
-- turrets and towers
-- by the sea
-- ancient ruins
-- caves
-- coves
-- huts
-- sheds
-- secret rooms or passages
-- green houses (hothouses)
-- attics
-- pavilions
-- graveyards
-- family burial plot
-- tunnels
-- basements
-- crypts
-- family burial vaults
-- ancient burial mounds
-- train
-- secret garden/garden maze (Thanks, Hannah!)
-- urban setting and its seamy elements: Urban Gothic (Thanks, Todd...)
-- right before or at Christmas
-- heroine's childhood home
-- sailboats
-- ships
-- orphanages
-- girls' finishing schools
-- Pagan ruins/in the woods
-- moat
-- the bayou/rural Louisiana
-- old springhouse
Supernatural Elements:
-- frightening animals (black dogs, hares, black cats, crows, etc)
-- familiars
-- incantations/spells
-- mist and fog
-- ghosts and spirits
-- voices
-- strange laughter
-- extrasensory perception
-- reincarnation
-- possession
-- patches of cold
-- mysterious lights
-- visions and nightmares with portents
-- Satanic books
-- devil worship
-- exorcism
-- curses and cursed items
-- voodoo
-- patches of cold air/rooms
-- phone calls from the beyond
-- seances
-- mediums
-- premonitions
-- omens
-- portents
Creepy/common elements:
-- old statues or figurines
-- family heirlooms like jewelry
-- medallions
-- talismans
-- voodoo dolls
-- porcelain dolls
-- exotic flowers
-- power blackouts
-- flickering lights
-- old books
-- mysterious letters
-- diaries or journals of the deceased
-- twins
-- mirrors
-- maps
-- secret panels
-- family portraits of the former, now dead, wife
-- family portraits of ancestors that seem to change
-- black candles used for rituals
-- sacrificial rites
-- old trunks of clothing or belongings
-- twisting, unsafe roads
-- paths in the woods
-- screeching birds
-- howling
-- footsteps in the hall
-- secret will
-- invisible horses and riders
-- peeping toms
-- masks
-- scorpions in the bed or in a shoe
-- snakes in the bed or in the room
-- poison
-- laudanum
-- opium abuse
-- marijuana abuse
-- sleepwalking (Thanks, Shaindel.)
-- bats
-- sleeping pills and lots of them
-- hallucinations
-- creaking doors that open and shut for no reason
-- skeleton keys
-- locked rooms
-- small, locked boxes
-- dust
-- rooms of the deceased that have been preserved and untouched
-- murders finally uncovered
-- murderers uncovered only after many years
-- literal skeleton hidden in a house
-- decaying corpse hidden in a trunk or in the basement (Thanks, Todd!)
-- death by drowning
-- house fires set by enemies
-- cobwebs
-- chippendale desks with secret drawers and cubbyholes
-- snuff
-- pipes/tobacco
-- lavender
-- violet
-- death couch where deceased loved ones were laid out
-- family birthmark that is passed down
-- death masks (and other parts to resemble the beloved)
-- jasmine
-- moss
-- cypress
-- tangled vines
-- whippoorwills
-- alligators
Taboo Elements:
-- incest or hints of it (Thanks, Shaindel!)
-- necrophilia or hints of it
-- lesbianism (Thanks again, Shaindel! I think this is your category.)
-- orgies (Um, Shaindel again. I'm sensing a pattern.)
-- rape or unwanted sexual contact with humans or ghosts
-- secret love child (~Hannah)
-- secret STDs like syphilus (~Hannah)
-- secret adulterous affairs resulting in children
-- ritual human sacrifice
-- murder/suicide that no one speaks of
Natural elements:
-- moaning wind
-- tree limbs scratching at windows
-- rain
-- sleet
-- storms
-- hurricanes
-- blizzards
-- lightning
-- thunder
-- fog
-- mist
-- full moons
-- no moon at all/dark night
-- mountains
-- willows
-- dense woods
-- unnatural stillness
-- dangerous cliffs
-- deadly sea
-- December, bone chilling weather\
-- fire
Classic foods and beverages in Gothic novels:
-- sauterne
-- sherry
-- whisky
-- gin
-- meal on a tray
-- spiked tea
-- port from the wine cellar
-- boiled puddings
-- broth
-- cigarettes (not a food but some characters smoke as if they are)
-- brandy
-- rum
-- buttered toast
-- black coffee
-- roast beef (this one seems to show up in every other Gothic Novel!)
-- quince jelly
-- speckled brown eggs