Mihrişah Valide Sultan Türbesi
This is part of a külliye built in 1794 by the mother of Selim III. It is, according to Strolling Through Istanbul, one of the largest and most elaborate of all the baroque complexes. What you see is the türbe of Mihrişah Valide Sultan herself.
One of several pictures I took during a visit in the early evening in May 2014. Many spots were much quieter than during the daytime, the mosque itself was still rather busy.
In this case with Eyüp I mean the area, rather than the mosque alone.