This one is a hideaway right in the centre of town, and for it to remain a secret we cannot actually reveal its whereabouts too clearly. What we can say is that it's on the roof of one of the city's bars, a clue being that this place is a bona fide wine cellar. Three storeys up, through a derelict attic room, there's a hidden balcony of about two by four metres, sheltered from the windows of the surrounding buildings. If you want to find this secret place, and be alone with a lover,  it's worth pointing out that spring/summer is the best time to do so, due to the lack of heating up there. The good news is that you're very unlikely to be disturbed.