The two Haunted Mansions have only minuscule differences. Neither is very scary, except maybe to very young children.
It could the House on Haunted Hill? There is a 1959 version and a 1999 version.
The 1959 original version of The House on Haunted Hill is not based in a mental institution. It is simply an old secluded mansion. However the 1999 remake of the movie does take place an an abandoned Asylum.
Cinnibar
Yes there is and its really different from the final version
There is no Pokemon Mansion, it was destroyed by the Volcanic Eruption in Cinnabar.
Cinnibar Island
The beta version wasn't released so you can't get it.
Cinnabar mansion
On Cinnabar Island
no
The size of a mansion is over 6000 square feet and has certain ammenities and styles that bring the building up in class. A mansion is a luxurious version of a house.
The Pokemon Mansion is home to some rare Pokemon. To find it in Pokemon Pearl version, go to route 212.