Passing under an arch in a dream represents a movement from one stage in your life to another.
It can symbolize moving to a new place, starting a new relationship, learning a new skill or taking on new responsibilities.
How do you feel as you walk beneath the arch? Are you happy, excited, nervous or frightened? What is the scene like behind the arch and in front of it? Does the place that you are walking toward appear beautiful and comforting or ugly and frightening? The way you see the place towards which you are traveling in the dream represents your feelings about your future.
Many bridges have arch shapes. Therefore, an arch in a dream can also represent a bridge, or a connection. It can represent a desire to form a new friendship or to reconcile with someone.