This staircase represents inspiration for how orphanage, The Seagull may look upon entrance. The left staircase to be used by the children. The right -- only to be used by self-professed and acclaimed (un-rightful) owners, Mr and Mrs Pinchfist.
The Winterlands is another 'world' hidden behind the 13 doors in ancient wood -- The Endless Forest. Jeremiah and his friends travel the waterways within the forest, but these are replicated in the Winterlands too -- though it's a very different world shrouded in eternal snow and cold.