Part of two hospitals taken up in London area (4)
I believe the answer is:
soho
'london area' is the definition.
(I've seen this before)
'part of two hospitals taken up' is the wordplay.
'part of' says the answer is hidden in the clue.
'taken up' shows that the letters should be reversed in order.
'ohos' is hidden within 'two hospitals'.
'ohos' back-to-front is 'SOHO'.
'in' is the link.
(Other definitions for soho that I've seen before include "District of London, noted for restaurants and nightclubs" , "Central London night life district" , "Nightclub area in London" , "Huntsman's call - area of London" , "London square" .)