Is Cape Coast Castle haunted?
Ghana Reported haunting level 5 of 5

What actually happened
Thousands of captive Africans were held in the castle's dungeons before being forced through the Door of No Return onto ships in the trans-Atlantic slave trade.
The history
The coastal fortress grew from a 1653 Swedish fort and became one of the major European trading and slave-trade centres on the Gold Coast.
What people report
Accounts of cries and movement in the dungeons are part of visitor tradition, but the documented suffering in those rooms needs no supernatural embellishment.
That paragraph is reported tradition, not a claim about what is there. The history above it is sourced; the stories are recorded because people tell them.
Visiting
Victoria Road, Cape Coast, Central Region, Ghana