To get to St. Fergus from Aberdeen, take the A90 northbound towards Peterhead and Fraserburgh. After approximately 30 miles, take the turnoff for St. Fergus. From Inverness, take the A96 south towards Aberdeen, then join the A90 northbound at Aberdeen and follow the same directions from there.
If traveling by rail, take the train to Dyce station outside Aberdeen, then switch to a bus or taxi for the remaining 35 miles to St. Fergus.
If you're visiting nearby towns or landmarks, consider stopping in Peterhead, which is only 9 miles away from St. Fergus, or the university town of Fraserburgh, which is 20 miles away on the same road.