Obscure bird seen to alight in dreamworld (15)

'dreamworld' is the definition.
I don't know anything about this answer so I cannot tell whether this works.

'obscure bird seen to alight' is the wordplay.
I cannot quite understand how this works, but
'obscure' could be 'cloud' (cloud can mean to obscure or conceal) and 'cloud' is found in the answer.
'bird' could be 'cuckoo' (cuckoo is a kind of bird) and 'cuckoo' is found in the answer.
'alight' could be 'land' (I've seen this before) and 'land' is found within the answer.
No letters remain.
This explanation may well be incorrect...

'in' acts as a link.

Can you help me to learn more?