Riddarfjärden (Swedish: [²rɪdːarˌfjæːɖɛn], "The Knight Firth") is the easternmost bay of Lake Mälaren in central . Stockholm was founded in 1252 on an island in the stream where Lake Mälaren (from the west) drains into the Baltic Sea (to the east); today the island is called Stadsholmen and constitutes Stockholm's Old Town.
The panorama picture featured in this article was taken from the heights of Södermalm, west of Stadsholmen, looking down on Riddarfjärden. Left to right are viewable:
Riddarfjärden throughout the year
Riddarfjärden in winter at Norr Mälarstrand
In the spring looking towards Långholmen
Early summer morning looking towards Södermalm
In the autumn, seen from Långholmen.
Coordinates: 59°19′26″N 18°02′55″E / 59.32389°N 18.04861°E