Board Thread:Questions and Answers/@comment-5808186-20170801093304/@comment-33883848-20190831155018

Delivers wrote: But they were in Waterfall, which by your logic, the monsters wouldn't have visited before Chara fell

The ancient glyphs were written when monsters lived in home/the ruins,after all the same glyphs says that monsters used cristals to go back "Home",the capital of the city while no one besides some random enemies and Toriel lives here anymore.