I really love roller coasters.
yes,  it is a type of amusement ride that employs a form of elevated railroad track 
I wonder how long people have been enjoying roller coasters.
The history dates back as far as the 17th century
Wow, I had no idea they have been around that long.  Where was the first one opened?
It is believed to have originated from the so-called "Russian Mountains"
The Russian Mountains?  I imagine that is in Russia?  Did they just lay tracks down the mountainside? 
:) in 1784, Catherine the Great is said to have constructed a sledding hill in the gardens of her palace