Revelation of Jesus Christ
From the KJV 1611 with Strong's Concordance
H5894
עִיר
'iyr
{eer}
(Chaldee); from a root corresponding to H5782; a watcher, that is, an angel (as guardian).
watchers
Daniel 4:17.
Watchers referenced in the book of Enoch
Enoch 1 (I) verse 5
Enoch 6 (VI) The Fall of the Angels (Watchers): the Demoralisation of Mankind
Interesting: The Hebrew word for 'city' H5892 'iyr {eer} is the same as the Chaldean word for 'Watcher'.