The largest cemetery in Uppsala is a beautiful place for a walk. Notable burials include the national romantic poet and historian Erik Gustaf Geijer; the poet Gustaf Fröding; artists Olof Thunman and Bruno Liljefors; Nobel laureates Kai Siegbahn, Arne Tiselius, Svante Arrhenius and the Nobel Peace Prize laureate Dag Hammarskjöld, who died under mysterious circumstances during his tenure as secretary general of the UN.