An interesting concept by Lithuanian engineer Julijonas Urbonas called the Euthanasia Coaster would be a roller coaster that would kill anyone who rode it. According to Julijonas the concept would “take the life of a person humanely, with elegance and euphoria” and would consist of a two minute climb up a steep peak followed by a high speed trip through loops designed to make all the blood rush from your brain eventually killing you.
If you were going to die anyway, is this how you would want to go out? See Julijonas discuss his concept in the video below.