# Why does the border of Northern Ireland have this unusual feature?

**URL:** <https://boards.straightdope.com/t/why-does-the-border-of-northern-ireland-have-this-unusual-feature/719540>\
**Category:** Factual Questions\
**Created:** [May 8, 2015, 9:36am UTC](https://boards.straightdope.com/t/why-does-the-border-of-northern-ireland-have-this-unusual-feature/719540 "2015-05-08T09:36:06Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![Atomic\_Alex](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/atomic_alex/32/175_2.png) [@Atomic\_Alex](https://boards.straightdope.com/u/Atomic_Alex)\
**Post date:** [May 8, 2015, 9:36am UTC](https://boards.straightdope.com/t/why-does-the-border-of-northern-ireland-have-this-unusual-feature/719540/1 "2015-05-08T09:36:06Z")

</div>

Not that the path the border between Northern Ireland and the Republic of Ireland follows is particularly logical in the first place but it has at least one particularly unusual piece of meandering.

I’m not sure how to get the grid reference, but if you check google maps there is a little enclave _(exclave?)_ of territory from the Republic projecting into the North, situated between Newtownbutler, Clones and Redhill. Actually 54.146427, -7.309804 should bring you to it.

In the space of just a few miles the N54 Cavan Road passes from NI into the Republic and back again.

Is there any particular historical reason for this?

---

<div class="post-metadata">

**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\
**Post date:** [May 8, 2015, 10:32am UTC](https://boards.straightdope.com/t/why-does-the-border-of-northern-ireland-have-this-unusual-feature/719540/2 "2015-05-08T10:32:47Z")

</div>

Historical border, the reason for which is lost to time, at least according to this:

> [@](#):
>
> To find out how this oddity first arose, you might have to go back to the Middle Ages. The McMahon clan, whose family business later became Monaghan, could probably explain. Or failing that, the Maguires, whose farming and feuding interests were likewise rebranded as modern-day Fermanagh.
> 
> The 1921 division inherited those lines. And this may be when the term polyp gained currency as a description for Drummully. The word has a detached, scientific sound about it; although it was hardly designed to reassure the populations on either side.

[Borderline Nationality Disorder - Drummully Polyp](http://www.irishtimes.com/culture/heritage/borderline-nationality-disorder-1.1530942)

---

<div class="post-metadata">

**Author:** ![Atomic\_Alex](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/atomic_alex/32/175_2.png) [@Atomic\_Alex](https://boards.straightdope.com/u/Atomic_Alex)\
**Post date:** [May 8, 2015, 10:38am UTC](https://boards.straightdope.com/t/why-does-the-border-of-northern-ireland-have-this-unusual-feature/719540/3 "2015-05-08T10:38:40Z")

</div>

Ah, thought it might be something like that, thank you 🙂

---

<div class="post-metadata">

**Author:** ![An\_Gadai](https://avatars.discourse-cdn.com/v4/letter/a/d6d6ee/32.png) [@An\_Gadai](https://boards.straightdope.com/u/An_Gadai)\
**Post date:** [May 8, 2015, 10:44am UTC](https://boards.straightdope.com/t/why-does-the-border-of-northern-ireland-have-this-unusual-feature/719540/4 "2015-05-08T10:44:57Z")

</div>

Here’s another article on that particular oddity: [365 - A Nameless Intra-Irish Pene-Enclave - Big Think](http://bigthink.com/strange-maps/365-a-nameless-intra-irish-pene-enclave)

Apparently the term is\* pene-enclave\*.

---

<div class="post-metadata">

**Author:** ![Atomic\_Alex](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/atomic_alex/32/175_2.png) [@Atomic\_Alex](https://boards.straightdope.com/u/Atomic_Alex)\
**Post date:** [May 8, 2015, 11:23am UTC](https://boards.straightdope.com/t/why-does-the-border-of-northern-ireland-have-this-unusual-feature/719540/5 "2015-05-08T11:23:32Z")

</div>

> [@An\_Gadai](#):
>
> Here’s another article on that particular oddity: [365 - A Nameless Intra-Irish Pene-Enclave - Big Think](http://bigthink.com/strange-maps/365-a-nameless-intra-irish-pene-enclave)
> 
> Apparently the term is\* pene-enclave\*.

Thanks!