在Exeter的東北。
For "where is it", you are using 是, which is grammatically wrong.
Instead, it should be 在哪儿呢？or eventually 在什麼地方呢？
You are confusing the two uses of "is" in English that include the senses of (1) being at a place, and (2) defining a category like in "X is a student".
In Chinese, both senses are strictly kept apart by using 在 for (1) and 是 for (2). It is wrong to mix them as you did.
Also, note that Chinese words can be flexible in terms of word class:
In certain cases, 在 can be used as (a) verb, when there is no other verbal predicate in a sentence, (b) as a preposition, when there is another verbal predicate in the sentence. However, 在 can never be used in combination with 是 in the same sentence.
Historically, Chinese prepositions developed from verbs indicating position.
Some type of interference (a technical term used in Contrastive Linguistics and foreign language teaching) from English tricked you in....LOL

I was speaking to another poster. However I gather North East of Exeter is a joke-a joke which I don't understand. As for the rest, Turnoi; you won't bog me down like you have been doing with another couple of posters. I simply have to repeat you do not know Chinese and you suppose nobody else does on the site. I can't and won't go 'in-depth' with a bloke so far out of his depth as to be laughable. Let's talk about the weather do.