Ideal place? Best one's in outskirts of Uppsala (6)
I believe the answer is:
utopia
'ideal place?' is the definition.
(I know that Utopia is a type of ideal place)
'best one's in outskirts of uppsala' is the wordplay.
'best' becomes 'top' (top can mean the very best).
'one' becomes 'i' (Roman numeral).
'in' is an insertion indicator.
'outskirts of' means to remove the middle letters (only letters on the outskirts).
'uppsala' with its middle removed is 'ua'.
'top'+'i'='topi'
'topi' put inside 'ua' is 'UTOPIA'.
(Other definitions for utopia that I've seen before include "Thomas More's 1516 book about life on an imaginary island" , "Impracticable state of perfection" , "Ideal but unattainable state" , "Ideal country" , "Ideal realm" .)