Complex sentence: Some churches north of the Antarctic Convergence serve Antarctic territories, so Christ Church Cathedral in Stanley is the southernmost Anglican cathedral in the world, and parish church not only for the Falkland Islands, but also South Georgia and the British Antarctic Territory.
Split into simpler sentences: Some churches north of the Antarctic Convergence serve Antarctic territories, such as the Christ Church Cathedral in Stanley, which is the southernmost Anglican cathedral in the world. It serves as the parish church not only for the Falkland Islands, but also South Georgia and the British Antarctic Territory.