A high viaduct carries you over a valley on many arches. It is read as getting across a difficult stretch of life with support, and as trust in a structure that holds you up high.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.