Ten-story collection at regular odeum in idyllic place (6)
I believe the answer is:
xanadu
'idyllic place' is the definition.
(I've seen this before)
'ten-story collection at regular odeum' is the wordplay.
'ten' becomes 'x' (roman numeral).
'story collection' becomes 'ana' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'at' is a charade indicator (letters next to each other).
'regular' indicates alternate letters.
The alternate letters of 'odeum' are 'du'.
'x'+'ana'+'du'='XANADU'
'in' is the link.
Can you help me to learn more?
(Other definitions for xanadu that I've seen before include "Where Kubla Khan decreed a pleasure dome" , "Site of Kubla Khan's pleasure-dome (Coleridge)" , "Kublai Khan's capital" , "Where Kublai Khan built his pleasure-dome" , "Idyllic location" .)