Climb aboard a local ferry to your first destination at the start of this fun island-hopping adventure. Sail to Hovedøya ("Main Island") where some of Oslo's best history and coastal scenery will be revealed. Learn how English monks came to Christianize post-Viking Oslo and set up a powerful abbey on the island nearly 1,000 years ago. Admire the well-preserved ruins as you walk among the chambers and rooms. Hear stories of Norway's transition from the Viking era to become part of a Christian Europe. Continue through sheep pastures and birch forests to arrive at the old ramparts and cannons from the 19th-century Napoleonic Wars. Explore the rugged coastline and stop at some beaches and lookout points before returning to the pier to catch another ferry to the island of Lindøya. Arrive at Lindøya and experience the charm of a summer retreat. See traditional wooden homes and gardens of flowers that contrast beautifully with the surrounding fjord. Get fantastic views from the summit of the island and work up an appetite for a picnic lunch. Stop at a local food store, if needed, to pick up something to eat. Enjoy your picnic on a southwest-facing beach and soak up the immense views of the water and hills. Then, jump on another ferry and sail past the island of Gressholmen, where the nature preserve is home to thick forest, sea cliffs and hidden beaches. Catch the ferry back to the city center and get an amazing entry into the port. Marvel at some of Oslo's most iconic sites, such as the old fortress of Akershus Festning, City Hall and the revitalized port of Aker Brygge.