Around 100km from top to bottom, the narrow straits and podgy basins of the Oslofjord link the capital with the open sea. This waterway has long been Norway’s busiest, an islet-studded channel whose sheltered waters were once crowded with steamers shuttling passengers along the Norwegian coast. The young Roald Dahl, who spent his summer holidays here from 1920 to 1932, loved the area, writing in his autobiography, Boy: “Unless you have sailed down the Oslofjord … on a tranquil summer’s day, you cannot imagine the sensation of absolute peace and beauty that surrounds you.” Even now, though cars have replaced the steamers, the Oslofjord makes for delightful sailing, and in good weather you can spy dozens of tiny craft scuttling round its nooks and crannies. The ferry ride from Oslo to Drøbak, a pretty village on the fjord’s east shore, provides a pleasant introduction to these nautical pleasures, though it’s not quite the same as having your own boat.
Today, both shores of the Oslofjord are dotted with humdrum industrial towns, and frankly, apart from the fjord itself, there’s not much to tempt you out of Oslo if your time is limited – especially as several of the city’s major sights are half-day excursions in themselves. But if you have more time, there are several places on the train and bus routes out of the city that do warrant a stop. The pick of the crop is the town of Fredrikstad, down the fjord’s eastern shore on the train route to Sweden – or rather the old part of Fredrikstad, which consists of an immaculately preserved fortress whose late sixteenth-century gridiron streets and earthen bastions snuggle up to the River Glomma. The fortress was built to defend the country from the Swedes, as was the imposing hilltop stronghold that rears up above Halden, an otherwise innocuous town further southeast, hard by the Swedish border. On the other side of the fjord, the highlight of the western shore is the cluster of Viking burial mounds at Borre, just outside the ferry port of Horten, while the breezy town of Tønsberg gives easy access to the shredded archipelago that pokes a rural finger out into the Skagerrak.