Is this a noun clause or an adverbial?

I'm interested in the following question:

I want to visit where my grandmother was born.

To me it seems like a noun clause because I could replace the clause with a noun. For example:

I want to visit Ireland.

Is this the correct way to check?

The definition I read for an adverbial clause states that Adverbial clauses of place modify the main verb in the sentence and provide information about the place that an action takes place. This definition has confused me about the difference between a noun clause and an adverbial clause.

How about the following sentences:

We can go wherever you want.

You can show me where it is.

Thanks for your help.

Patrick.