The Collaborative International Dictionary of English v.0.48:

Wonderland \Won"der*land`\, n.
   A land full of wonders, or marvels. --M. Arnold.
   [1913 Webster]

WordNet (r) 3.0 (2006):

wonderland
    n 1: a place or scene of great or strange beauty or wonder
    2: an imaginary realm of marvels or wonders

Moby Thesaurus II by Grady Ward, 1.0:

41 Moby Thesaurus words for "wonderland":
   Agapemone, Arcadia, Big Rock-Candy Mountain, Canaan,
   Cloudcuckooland, Cockaigne, Eden, Eldorado, Erewhon,
   Garden of Eden, Goshen, Happy Valley, Land of Youth, Laputa,
   Never-Never-land, Neverland, New Atlantis, Pandemonium, Quivira,
   Shangri-la, Utopia, Zion, arcadia, cloudland, dreamland, dystopia,
   faerie, fairyland, heaven, kakotopia, kingdom come, land of dreams,
   land of enchantment, land of faerie, land of plenty,
   land of promise, lotus land, millennium, paradise, promised land,
   utopia