A chapel
A small church that is not a parish church. It may be part of a larger entity such as a hospital, school, or an alms-house, or it may stand alone.
An enclosed part of a church with its own altar.
along one of the straight side walls of the choirIn a church with a cruciform floor plan, the part of the church that lies on the side of the nave opposite to the transept. The main altar is in the choir..