Extracts from the following book – Places not on Google Maps
The Basilica Ballcock
This device in the Basilica Cistern, made from pumice polished for four months by eunuchs, regulates the flow of water into the city’s underground reservoir. It is connected to a stone lever which closes when the ballcock touches the ceiling of the cistern. The Ballcock is about a thousand years old and the whole mechanism is based on an earlier design of Hero of Alexandria, although Hero’s original contraption was steam powered.
The Herb Bazaar
This bazaar is close to the Spice Bazaar, but only sells seeds for vegetables and for herbs used to grow in herb gardens. This bazaar employs hawks to scare away smaller songbirds, who would otherwise eat the seeds. This bazaar has the best coffee shops in Istanbul and is not frequented by many tourists. Locals sometimes bring items to barter and this is the only such market in Istanbul to allow this practice.
The Green Mosque
This mosque is covered in solar panels and has wind turbines on the top of its four minarets to help with electricity generation. Visitors walking along the entrance carpet generate kinetic energy that powers the lights in the main prayer hall.