Yarimburgaz Cave

Yarimburgaz Cave - TAY Project

As I was writing Burnt Amber, I had a cave in mind for a key location. Plenty of mythology pointed to the place. When I started writing the Istanbul section of the story, I was hard-pressed for a cave with the local lore I needed. Good thing I watch  Muhteşem Yüzyıl - or I should say, good thing the producers got in legal trouble for using an interesting cave in one of their episodes. Now I have the perfect setting for a scene I've been thinking up...

Details of the Yarimburgaz cave:

• Located in the Küçükçekmece area, near Istanbul 
• Formed by and underground river, the double mouthed cave is known for it's prehistoric significance. The earliest evidence of human settlement in Turkey was found there. 
• Site of a Byzantine church or monastery, similar to many caves in Turkey. 
• Much archaeological evidence had been destroyed before the official dig. This was due to amateur interest in the old caves, and the worst offender - a mushroom farming operation.
• Iron bars on the cave are supposed to inhibit people from entering. 

Muhteşem Yüzyıl producers are accused of using the cave as a setting, and digging a "hot spring" inside.
My question is this: Who unlocked the gates? And how did no one notice a film crew setting up there? The cave has been used in previous films and TV shows, so maybe no one thought anything of it?