To get to the Sancaklar Mosque from central Istanbul, go out to an interchange station and take the metrobus to the last stop west.
That is Beylikdüzü Son (last) Durak (stop). As it's the end, it is difficult to miss. You have done the main part of the journey for maybe £2, return. Then negotiate with a taxi to go, wait and return. That could cost you a bit over £30, but it's worth it.
You've explored many Ottoman mosques and admired the decorative stonework, windows, and especially the tiles. There has been some stylistic development since Sinan in the 16th century, but not much. Prepare to be shocked and amazed by the minimalism of the Sancaklar.
The Sancaklar is built into the ground on the crest of a ridge. There is domestic building on one side, and unfortunately more development around, but it should retain its panorama. From the outside, only the square block minaret stands out.
Set in a garden, the mosque is built of Bodrum slate facings on a concrete core. Think English lake district Honister, and it's close.
The mosque was sponsored by the Sancaklar family. A Sancak was an administrative region in the Ottoman empire and by inference the person holding office there. A Sancak roughly equates to an English shire.
The garden slopes down
There are embedded steps to the lower level.
The grass might not stand thousands of visitors, but no problem so far
The slate is placed in slopes and angles to provide abstract vistas
Seat and shadow
Occasional vista
Cool corridor
Inside is the rack for shoes, or you can leave them outside
There are no large windows in the prayer hall, so everything is down to the lighting designers.
The prayer hall has all the essential requirements of a mosque but they are reduced to minimal abstract forms. It does help to know what is what, if only by contrast to the 'usual' elaborate mosque
The roof is concrete and stepped over the hall. The whole is considered to represent the cave where the word of God was revealed to Mahommet
Another view of the roof against the Quibla wall
The Mimbar as semicircular steps leading to a niche
Koran reader by the Mimbar
The Mihrab reduced to a gap in the wall. The lighting from above is natural. The wall is in boarded concrete