A verb of motion and "a la playa, casa, tienda" and the like indicate a movement toward. The Duo drop downs offer options, but not all or correct for any given sentence. "como" can mean "I eat" and "how," depending on the context, and both options are in the drop down.
I said, "The professor walks to the beach." When we translate "teacher" to Spanish, we can use "profesor" or "maestra" and it is considered correct. I thought it could go the other way, as well. But it was counted wrong. Maybe it isn't a specific enough translation?