may have been a pillar, was also symbolic of the center of the world. Davidson details that it would be difficult to ascertain whether a tree or pillar came first, and that this likely depends on if the holy location was in a thickly wooded area or not. Davidson notes that there is no mention of a sacred tree at Þingvellir in Iceland yet that Adam of Bremen describes a huge tree standing next to the Temple at Uppsala in Sweden, which Adam describes as remaining green throughout summer and winter, and that no one knew what type of tree it was. Davidson comments that while it is uncertain that Adam's informant actually witnessed that tree is unknown, but that the existence of sacred trees in pre-Christian Germanic Europe is further evidenced by records of their destruction by early Christian missionaries, such as Thor's Oak by Saint Boniface. Ken Dowden comments that behind Irminsul, Thor's Oak in Geismar, and the sacred tree at Uppsala "looms a mythic prototype, an Yggdrasil, the world-ash of the Norsemen". Modern influence Thomas Carlyle adopted "Igdrasil" as a favorite symbol; it features in both On Heroes, Hero-Worship, & the Heroic in History (1841) and Past and Present (1843). John Ruskin used it in the conclusion to The Laws of Fésole (1877–1878), and it was adapted for the title of the Ruskin Reading Guild Journal by its editor in 1890, based on a manuscript of Carlyle's. Modern works of art depicting Yggdrasil include Die Nornen (painting, 1888) by K. Ehrenberg; Yggdrasil (fresco, 1933) by Axel Revold, located in the University of Oslo library auditorium in Oslo, Norway; Hjortene beiter i løvet på Yggdrasil asken (wood relief carving, 1938) on the Oslo City Hall by Dagfin Werenskiold; and the bronze relief on the doors of the Swedish Museum of National Antiquities (around 1950) by B. Marklund in Stockholm, Sweden. Poems mentioning Yggdrasil include Vårdträdet by Viktor Rydberg and Yggdrasill by J. Linke. In Overlord, a Japanese light novel series written by Kugane Maruyama, Yggdrasil is the name of a popular DMMORPG, where the protagonist got trapped after its shutdown. See also Axis mundi, mythological concept representing "the connection between the higher and lower realms" Notes References External links Locations in Norse mythology Trees in Germanic paganism Trees in Germanic mythology Trees in mythology