It solely depends on the context. Using "the" indicates that you are refering to a particular town with some sort of special implication. To illustrate a bit: "I'm almost at home." vs "I'm almost at my home." The latter emphasizes the ownership of the place mentioned. In short: It is correct, but the "the" isn't necessary, unless there is something special about "the" town you're referring to.

We've almost arrived at the town or I've almost arrived at the town depending on 1 or more people.