There's two things to understand the comment. In the UK, "a hole" means that a place is bad. I think you could probably translate this into more international

There's two things to understand the comment. In the UK, "a hole" means that a place is bad. I think you could probably translate this into more international English by making a similar pun on "Colchester is already a dive", but it doesn't work quite as smoothly. Secondly, Colchester is a principal part of Essex, which vies with Newcastle for being the UK's New Jersey, but in a worse way than Newcastle. Wikipedia has several articles on the pejorative Essex stereotypes. Colchester also has a major military base, which makes it a center for squaddies[0]. [0] https://www.urbandictionary.com/define.php?term=squaddie https://www.urbandictionary.com/define.php?term=squaddie