The stone that named the town - Sigtuna's ancient mystery

Nyckelstenen, a flyttblock at Mälarens strand, approximately half a mile from Sigtuna, is mentioned in several sagas related to the sacking of Sigtuna in 1187 [1]. Among these tales, one suggests that the key to Mariakyrkans portar was dropped nearby during the raid. But the stone's exact location remains a mystery. Martin Aschaneus, in 1612, mentioned a cape named Sigtuna Nykell [1], suggesting that the stone was once called that. By that time, the legend was not yet widespread.

Nyckelstenen is depicted in Suecia Antiqua et Hodierna, based on a drawing made in 1695 [1], where it is simply described as notable for the remarkable form nature has given it. The stone was depicted again in Georg Wallins Sigtuna stans et cadens (1729-32) [1], where it is briefly mentioned and its painted keys, but nothing about its legends. Johan Fischerström, in Beskrifning om Mälaren 1785, wrote that the impression suggests that the keys were carved out [1].

At the time, the stone's painted keys had faded and were no longer visible. The legend of Nyckelstenen, the stone where the key to Mariakyrkans portar was lost, is first described in A.H. Wistrand's Sigtuna det forna och det nuvarande (1847) [1]. By that time, the stone’s location had long been forgotten. The stone was ‘rediscovered’ in 1966 by Jan Peder Lamm, who had last repainted it in 1922 or 1923 [1]. Lamm has assumed that the stone, which originally marker the channel leading to Sigtuna and was called ‘Mykil steen’ (the great stone) [change from 2], may have been corrupted to nyckelstenen (key stone) [change from 2] and eventually given rise to the legend.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons