Nävsjön
It straddles the boundary between Norrköping Municipality in Östergötland County and Nyköping Municipality in Södermanland County . 
<triplet> Norrköping Municipality <subj> Östergötland County <obj> located in the administrative territorial entity <subj> Nyköping Municipality <obj> shares border with <triplet> Östergötland County <subj> Norrköping Municipality <obj> contains administrative territorial entity <subj> Södermanland County <obj> shares border with <triplet> Nyköping Municipality <subj> Norrköping Municipality <obj> shares border with <subj> Södermanland County <obj> located in the administrative territorial entity <triplet> Södermanland County <subj> Östergötland County <obj> shares border with <subj> Nyköping Municipality <obj> contains administrative territorial entity