Religious services? (Muscat)

Hi all!!! Happy Eid and Happy Sunday! I have a question about the possibility of any Sunday services away from the capital? Are there groups who go to Muscat to worship at one of the many churches there on a regular basis whom I can join? Is this frowned upon there? Are there any services in Nizwa of any kind? Kind of have to work around the different weekend days there and Sunday services I guess, eh? I am very interested to hear anyone's experiences with Sunday worship (in particular, RC Mass?). Thanks!!