Oscarsborg is only accessible by boat. A ferry service runs every day all year from Drøbak to Oscarsborg Fortress. The crossing from Drøbak takes about 10 minutes. If the weather is good, we recommend sitting on the sun deck. Check the ferry timetable in advance since summer and winter schedules differ.
It is easiest to get from Vollen to Drøbak by car, although for some weeks in June and July there is a weekend ferry route. Drive south past the villages of Nærsnes, Båtstø and Åros to Sætre and then take route 23 through the 7 km Oslofjord tunnel to Drøbak. Follow signs for the Oscarsborg ferry which leaves from the harbour and arrives at the west of the island.