The noun town when used with prepositions does not take an article:

#1. when we mean the nearest town (if we live in the country) or the town we live in.

You cannot go to town tomorrow. (Austen)

What can you have to do in town…? (Austen)

#2. when the noun town is opposed to the noun

He was not used to country life, having spent twenty years in town.

Otherwise, the noun town is used with the definite or indefinite article.

 I want to go to the town where I was born.