I wouldn't get closer, it's quite hot up there.
Techo Mountain (also known as the Mystery Island Volcano) is a Mystery Island landmark that allows users to exchange ten tan codestones for a red one (which can be used at the Secret Ninja Training School to train level 250+ pets).
Site Description[]
" Welcome to the Mystery Island Volcano! It was recently discovered that by throwing normal codestones into the volcano you can get special Red Codestones out. These magical stones will help your Neopet advance their skills beyond the training offered at the Training School. "
Other Methods of Obtaining Red Codestones[]
Back in 2004, when Techo Mountain was introduced, it was the cheapest way to get red codestones. However, since then, they were made obtainable from Key Quest, the Battledome, as well as other players, effectively making the Volcano obsolete.
External Links[]
Volcano Codestone Conversion on Neopets