Here's s page of wonderful images of the great mosaic icon of Christ in the upper gallery of Hagia Sophia - otherwise known as Saint Sophia.
The garden is found next to the Church of the Nativity of the Virgin, at the end of the Corridor of the Maids of Honor. It links the Grand Palace to the Apartments of Their Majesties.
The greenhouses of the Alexandrinskii Summer Palace provide the plants for the Winter Garden.
One will note an adventurine vase in the garden, made out of one solid block, and a statue in marble, depicting Hercules and Vesta.