Final answer:
The incorrect tense in the paragraph is 'leaved', which should be 'leave'.
Step-by-step explanation:
The verb in question is 'leaved', which is an incorrect tense. The correct tense should be 'leave'. The sentence should read: 'In London, I leave Buckingham Palace, the royal residence of the queen.' The verb should be in the present tense to match the rest of the paragraph which is written in the present tense.