page_title: Rundetaarn
section_title: Planning and preparations
hierarchical_section_title: Rundetaarn / History / Planning and preparations
caption_attribution_description: From Hafnia Hodierna by Laurids de Thurah, 1748. Drawings of buildings in Copenhagen. Tab.XC. Rundetårn.
context_page_description: The Round Tower, formerly Stellaburgis Hafniens, is a 17th-century tower located in central Copenhagen, Denmark, and one of the many architectural projects of Christian IV of Denmark, built as an astronomical observatory. It is most noted for its equestrian staircase, a 7.5-turn helical corridor leading to the platform at the top, and for the expansive views which it affords over Copenhagen.
  The tower is part of the Trinitatis Complex which also provided the scholars of the time with a university chapel, the Trinitatis Church, and an academic library which were the first facilities of the Copenhagen University Library which had been founded in 1482. Today, the Round Tower serves as an observation tower for views of Copenhagen, a public astronomical observatory, and a historical monument. The Library Hall above the church is only accessible along the tower's ramp and is a venue for exhibitions and concerts.
context_section_description: After Tycho Brahe had fallen out of favour and left Denmark, Christian Longomontanus had become Christian IV's new astronomer and the first professor of astronomy at the University of Copenhagen. In 1625 he suggested the king build an astronomical tower as a replacement for Brahe's Stjerneborg which had been demolished Steenwinckel|publisher=answers.com|accessdate=2009-11-26}}</ref>
  Longomontanus' initial proposal was to erect the new observatory on the top of the hill Solbjerget, now known as Valby Bakke. But since there were also plans for the construction of a new students' church and a library for the university, the idea of merging the three buildings into one grand complex emerged.
  Already in 1622, Christian IV had bought the land where it was ultimately decided to build the Trinitatis Complex. His original plans for the site are not known but as it was conveniently located next to the Regensen dormitories and the university, it was chosen for his new prestigious project.
  Although there is no clear proof, it is generally accepted that Hans van Steenwinckel the Younger was charged with the commission to design the new edifice though he did not live to see the tower completed. 
  From 24 November 1636, stones were brought to the site for the foundation, first from the city's ramparts and later from the area around Roskilde. Bricks were ordered from the Netherlands since local manufacturers could not meet the high quality standards requested. In February 1637, a contract was signed with a Henrik van Dingklage in Emden for the supply of bricks for the construction. The first three ship loads were to be delivered in May, the next three loads the following month and the remainder on demand.
  The Trinitatis Complex was set for construction in a crowded neighbourhood of narrow streets and alleyways. The area first had to be cleared. On 18 April 1637, 200 men, soldiers and personnel from Bremerholm began to demolish the half-timbered houses occupying the site.
caption: Cross section of the tower and the church from Thurah's Hafnia Hodierna
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