Mythical city found in field or a dockland (2,6)
I believe the answer is:
el dorado
'mythical city' is the definition.
'el dorado' can be an answer for 'city' (I've seen this before). I'm not sure about the 'mythical' bit.
'in field or a dockland' is the wordplay.
'in' says the answer is hidden in the clue.
'EL DORADO' is hidden in the letters of 'field or a dockland'.
'found' is the link.
Can you help me to learn more?
(Other definitions for el dorado that I've seen before include "Imaginary land of riches" , "A doodler in fabled land of gold" , "Fabled wealthy place" , "'Imaginary place of great wealth and opportunity (2,6)'" , "Fabled city of great riches" .)