See this meta question, where two questions covering similar topics got merged:
- What Is The Difference, If Any, Between "Permanent", and "Until Dispelled"?, and
- Can a permanent teleportation circle be dispelled?
However, the merge was in error, as the Permanent vs Until Dispelled question does not apply to the Teleportation Circle question, since the duration of Teleportation Circle is not Permanent.
To clarify the issue with merging these questions: Suppose that the answer to the Circle question is "Yes, because permanent means until dispelled and permanent in the name means it's a duration of permanent." This answer makes sense under the Circle question, but not the Difference question.
On the other side, the stance I take: "No, because it's not a Permanent duration spell, and only the spell itself (which lasts one round) can be dismissed." This answer makes even less sense under the question it got merged into. (As a side note, Sage Advice: Can you use dispel magic on the creations of a spell like animate dead or affect those creations with antimagic field? seems to agree, or at least hint at RAI agreeing.)
Should we un-merge these questions?