Glenfinnan Viaduct is best known for the steam train that snakes across it, so if you want that iconic shot book Jacobite train tickets and check the timetable in advance because it runs seasonally and the crossing times are precise. Park at the Glenfinnan Visitor Centre (small fee), use its toilets and cafe, then take the short walk to the main viewpoint or down to the shoreline for a different angle; the shoreline path is uneven and not suitable for all mobility levels. Expect crowds when the train passes, so go early morning or late afternoon for fewer people and better light, and whatever you do do not climb on the viaduct or ignore safety signs. You can also reach the site by the West Highland Line from Fort William but services are limited, so plan connections ahead.