Which of the following sentences is better?
There is one museum in this city.
This city has one museum.
Either of these is fine, and there’s no particular difference between them.
However, you use one museum in such a short sentence only if you mean that the city has only one museum. If this is not the case, you say a museum unless you are going to single out one particular museum you are talking about.
There is one museum in this city you must not miss.
This city has one museum with an international reputation.
Source : Link , Question Author : brilliant , Answer Author : StoneyB on hiatus