There seems to be a misunderstanding in the question. There is no such thing as a "second tallest mountain on Earth".

Here's why:

* Mount Everest is the tallest mountain on Earth: It reaches a height of 8,848.86 meters (29,031.7 feet) above sea level.

* "Second tallest" implies a ranking: We can rank mountains by their height, and the second-tallest mountain on Earth is K2, located in the Karakoram Range of Pakistan and China.

Therefore, the "tallest second mountain" is not a valid concept. It is either the second tallest mountain or the tallest mountain, but not both.