This Bible contradiction is from the Skeptic's Annotated Bible.

Verses

They were given to Judah.

Joshua 15:20 View context

This [is] the inheritance of the tribe of the children of Judah according to their families.

They were given to Dan.

Joshua 19:40-41 View context

[And] the seventh lot came out for the tribe of the children of Dan according to their families.

And the coast of their inheritance was Zorah, and Eshtaol, and Ir-shemesh,