East Side of the Fjord
The road from Oslo leads down the east side of the fjord to the attractive seaside resort of Drøbak in Østfold county, lying off the main road, with a handsome wooden church (1736), the Treegaarden Julehus ("Christmas House") and the castle of Oscarsborg in the Oslofjord, where the German heavy cruiser "Blücher" was sunk in April 1940.
South along the Oslofjord is the town of Moss (pop. 25,000), on the Mossesund, which separates the island of Jeløy (Alby manor house, with the F 15 Gallery) from the mainland (bridge). Archeological finds indicate that the area was settled as far back as 7000 years ago. It was prominent during the Iron Age, Viking Age as as well a major port, which still holds true today. The treaty of union between Norway and Sweden was signed at Moss in 1814. Car ferry (45 minutes) to Horten, on the west side of the Oslofjord. To the south, on the shores of the fjord is the seaside resort of Larkollen.
The main road along the Oslofjord runs to Sarpsborg (pop. 12,000), originally founded by St Olav in the 11th century. It is now a busy industrial town (papermaking, cellulose, electrical engineering). Borgarsyssel Open-Air Museum (old houses, pastor's house of 1660, ruined church of St Nicholas, built by King Øystein in the 12th century); beautiful Kulås Park (Iron Age burial mound).Sarpsborg, originally known as Borg, has been rebuilt on several occasions. It has grown steadily reaching 50,000 in 2005. Sports are popular with a well-known football and hockey team.
To the west of Vikene there is a ferry to the island of Hankø (beautiful coniferous forest), now a popular holiday resort, with a sailing school.
Oldtidsveien - Rock Carvings
Between Fredrikstad and Skjeberg (pop. 13,500) runs the "Prehistoric Trail" (Oldtidsveien), along which are a series of prehistoric remains: rock carvings at Solberg (human figures, solar symbols, ships) and Hornnes (ships with animals' heads on the prow), 200 burial mounds at Store Dal Felt and rock carvings at Begby, including solar symbols, human figures, animals, and men with swords and phalluses (Bronze Age).
On the east side of Oslofjord 2km/1.25mi before the Swedish frontier a road branches off on the left to Halden (pop. 26,000). The town, known from 1665 to 1927 as Frederikshald, withstood several attacks by the Swedes and after suffering severe damage in a fire was rebuilt on a regular plan in 1826. It has a variety of industries, including particularly woodworking, and is an important center of the timber trade in eastern Norway.Halden has a notable music culture with regular concerts featuring a variety of artists and orchestras. Outdoor concerts are also very popular during the summer months. The town of Halden hosts numerous festivals such as the Wooden Boat Festival in July and a Croquet Festival in August.
On the high ground to the east of Halden stands the fortress of Fredriksten (alt. 113m/370ft; fine views), built in 1661-71. An iron pyramid (erected 1860) commemorates King Charles XII of Sweden, who was killed during the siege of the town in 1718. Here too is the Municipal Museum (Haldens Minner).
Rø Manor House
Halden has a theater in the manor house of Rø (1830), with a Baroque stage. On the east side of the town is the Atomic Energy Institute, with a reactor which came into service in 1959.