Roslagen

Skärgårdsstad is a locality situated in Österåker Municipality, Stockholm County, Sweden with 1,924 inhabitants in 2010.

Härsbacka mine (Swedish: Härsbacka gruva) is a quartz and feldspar mine. It was once Sweden's foremost quartz mine. The mine was closed in 1946. The quartz and feldspar mined in Härsbacka are the main constituent of a large pegmatite dyke. This pegmatite dyke dips about 60 to 70° to the southeast and has a maximum thickness of 37 m. While quartz and feldspar are mostly mixed, pure zones of either occur. Most feldspar is pink microclineperthite and much lesser amounts are white oligoclase. There are lesser quantities of biotite, garnet, molybdenite and fluorite. About 230,000 tons of quartz have been mined in total from Härsbacka mine. In 1947 the mine was bought by Statens Vattenfallverk to turn it into an oil storage depot and it functioned as such until 1985 when it was emptied. Since 1997 the mine is fully flooded by groundwater. In 2021 the Geological Survey of Sweden was tasked with investigating contaminants in the mine.

Bammarboda is a locality situated in Österåker Municipality, Stockholm County, Sweden with 249 inhabitants in 2010.

Solberga () is a locality situated in Österåker Municipality, Stockholm County, Sweden with 409 inhabitants in 2010.

Mjölkö or Mjölkön is an island in Österåkers municipality about 3 km east of Åkersberga. The island consists of around 120 residences and the number of residents during the 2000s has been few. The Mjölkö community association manages approximately 10 km gravel roads, several docks, and water areas around the island. The association also arranges midsummer celebrations and other social activities. The island is operated by Waxholmsbolaget. The island's name is derived from that the mainland farmers used to have their cows on the island during the summer months and traveled there every day to milk them.

Skarpö is an island in the Stockholm archipelago in Sweden. It is situated in Vaxholm Municipality and Stockholm County. The southern and western half of the island comprises the Skarpö urban area. A road bridge and local road connects Skarpö to county road 274 on the adjoining island of Rindö to the south. Rindö is in turn connected to Vaxholm town by the Vaxholmsleden car ferry at its western end, and to Värmdö island by the Oxdjupsleden car ferry at its eastern end. To the west, Skarpö is separated from the island of Stegesund by the very narrow Stegesundet strait, which is used by Waxholmsbolaget ships, and other local ferries, that serve the outer archipelago. Some of these call at Skarpöborg pier on the Skarpö shore of the Stegesundet strait, providing a connection to Vaxholm town and Stockholm city.

Österåker Municipality (Swedish: Österåkers kommun, IPA: [ˈœ̂sːtɛrˌoːkɛʂ kʊˈmʉːn]) is a municipality in Stockholm County in east central Sweden. Its seat is located in the town of Åkersberga, with a population of 26,727 (2005). From 1974 to 1982 Österåker was part of Vaxholm Municipality. Its location by the Stockholm archipelago, in the Roslagen area, attracts both people who settles here, often commuting to Stockholm, and visiting tourists. Österåker boasts several golf courses, many possibilities for canoeing, horse riding, fishing and other nature activities. Österåker also has a historical significance, with at least three notable castles from the 17th and 18th centuries, with histories tracing even further back. Sweden's once largest quartz mine, the Härsbacka mine, lays within the municipality.Like many other municipalities making up Metropolitan Stockholm, Österåker has a significant outward-commuting mainly to Stockholm, with some 13,000 commuters.

Åkersberga is a locality and the seat of Österåker Municipality, Stockholm County, Sweden with 28,033 inhabitants in 2010.

Stegesund-Hästholmen is an island, sometimes considered a pair of islands, in the Stockholm archipelago in Sweden. Stegesund-Hästholmen is situated in Vaxholm Municipality and Stockholm County. Hästholmen (to the west) and Stegesund (to the east) are separated by an artificial channel, constructed in 1899, and connected by a bridge. The island has a permanent population of about 20 people. To the north, west and south, Stegesund-Hästholmen is separated from the islands of Resarö, Edholma and Vaxön by the winding northern section of the Kodjupet strait, whilst to the east it is separated from the island of Skarpö by the much narrower Stegesundet strait. The artificial channel between Stegesund and Hästholmen is only navigable by very small boats, such as dinghies and canoes. Stegesund-Hästholmen has no road connection to the mainland or other islands. It is served throughout the year by passenger ships of the Waxholmsbolaget, which call at either the Vikingsborg pier (on Hästholmen) or the Stegesund pier (on Stegesund), providing a connection to Vaxholm town and Stockholm city.

Österskär is the eastern part of Åkersberga, Österåker Municipality in Sweden. It hosts the terminal station of the Stockholm suburban railway Roslagsbanan. The area is located in a hilly peninsula between Tunaviken and Sätterfjärden northwest of Trälhavet. Many Stockholmers have their boats in one of Österskär's many marinas. There is a residents association.

Stegesundet is a very narrow strait in Sweden's Stockholm Archipelago. It separates the islands of Stegesund-Hästholmen (to the west) and Skarpö (to the east), and provides a shorter route than the section of the Kodjupet strait that passes to the west of Stegesund-Hästholmen. The strait is too restricted for most commercial shipping, but is used by pleasure craft, Waxholmsbolaget ships, and other local ferries. Some of the Waxholmsbolaget ships and local ferries call at Stegesund and Skarpöborg piers on either side of the strait.

Ytterby (Swedish pronunciation: [ˈʏ̂tːɛrˌbyː]) is a village on the Swedish island of Resarö, in Vaxholm Municipality in the Stockholm archipelago. Today the residential area is dominated by suburban homes. The Swedish name of the village translates literally into "outer village". Ytterby is the single richest source of elemental discoveries in the world; the chemical elements yttrium (Y), terbium (Tb), erbium (Er), and ytterbium (Yb) are all named after Ytterby, and the elements holmium (Ho), scandium (Sc), thulium (Tm), tantalum (Ta), and gadolinium (Gd) were also first discovered there. Local roads connect Ytterby to county road 274 and hence the mainland. Except for the winter months, passenger ships of the Waxholmsbolaget call at a pier in Ytterby, providing a connection to Vaxholm town and Stockholm. Ytterby is as well served by several local bus lines of the north east SL district, connecting the area directly to Stockholms Östra station.