User blog comment:Sargenttacos115/Natsu and Gajeel age Theory/@comment-67.238.183.187-20130414173647

All the dragon slayers are from 400 years ago due to the fact no one in the current time has seen a dragon, but them. Mavis or Makarov have never commented on ever seeing a dragons. That's why Natsu and Gajeel could not pass through the ruins.