Our wonderful traditional Christmas Party is back this year at Roswyn House and we can't wait to welcome you all and have some festive cheer! The event is nearly here and tickets are selling fast, so please order ASAP and we look foward to setting the atmosphere for the Festive Season. Roswyn House, 13 Streatham Common South, London. SW16 3BT. The London Residence of The Lady Ratlings.