Loviisa. Located 54 miles east of Helsinki, this town belies the strong Russian influences along flavors of the eastern branch. There’s a historic residential district, the notable island fortress of Svartholm, and a pair of land fortresses (Ungern and Rosen) that offer insight into how the Swedes and Russians guarded the King’s Road from raids.
[...]

Turku. This is Finland’s oldest town, third largest city, and former territorial capital (until Sweden lost Finland to Russia in 1809). Turku is the western terminus of the King’s Road and a ferry port to Stockholm and the Aland Islands. Topping the list of historic attractions are the sprawling 13th-century Turku Castle — Finland’s best-known [...]

During the 600 years Finland belonged to the Sweden, the Swedish royal court and its couriers traveled a road through Finland that ran to St. Petersburg. Hamlets, castles and forts sprung up along what naturally came to be called "The King’s Road."
In modern times, the route consists of two branches of comfortably paved country [...]