And will it still be valid in the eyes of the church?
If both parties to a marriage are Catholic then the marriage must take place in a church or chapel unless there are extreme circumstances that make it extremely impractical. Such situations are extremely rare and are as such rarely permitted.
If one of the parties is not Catholic then the couple can request a dispensation to be married in another suitable place. However, while the burden to prove a Catholic wedding would be problematic is lighter, there must still be a compelling reason for the Catholic to either not be married in a Catholic church or, if the other person is a baptized Christian, in the faith community of the other spouse. So in this situation it is possible, but it is not automatic.