Source:
https://www.booksfact.com/archeology/jama-masjid-ahmedabad-bhadrakali-temple.html
The Jama Masjid in Ahmedabad was originally A Bhadra Kali temple. It was converted into a mosque by Ahmed Shah I. The intricate flowers, coiled serpents representing Kundalini and bells, the remnants of the glorious temple that it may have been. Such carvings are banned in Islam. This goes on to support the history of the temple. Goddess Bhadrakali was believed to be the Nagar Devi of Ahmedabad.
One of Ahmedabad’s ancient names was Bhadra which was after Devi Bhadrakali. Ahmedabad was named after Ahmad Shah I of the Muzaffarid dynasty who forcibly captured “Karnavati” in 1411.
Bhadrakali temple is believed to be one of the oldest temple of Ahmedabad and located inside Bhadra Fort in center of city.The exact date of construction is not known but as per the evidence this holy shrine existed at least for more than 800 years. This shrine is dedicated to goddess Bhadrakali and believed as Nagar Devi of Ahmedabad. It is believed that Karndev, King of Patan and founder of Karnavati on bank of River Sabarmati, had established the Bhadrakali temple.

Filigree carvings of flower and Paisley motifs, lotus flowers and creepers, mandalas, elephants, coiled serpents representing the kundalini, celestial dancers and bells are found carved on the 100 odd surviving pillars that line the temple complex.
If this was originally supposed to be a mosque built with a large hall for mass prayers, then what would be the purpose of having so many pillars in between ?
Most of the pillars are carved in typical hindu temple style.
Mosques have large halls or open places where many can offer namaz (prayer) at a time.
Wouldn’t the pillars cause an obstruction while offering Namaz ?
Many hindu temple pillars are usually carved with stories from the Puranas, Vedas and Itihasas like Ramayana and Mahabharata.
The original Bhadra fort still exists in distorted shape.
Jama Mosque is situated outside Bhadra Fort area, along the south side of the road extending from Teen Darwaza to Manek Chowk.
Ahmedabad was named after Ahmad Shah I of the Muzaffarid dynasty who captured Karnavati in 1411. He established Ahmedabad as the new capital of Gujarat Sultanate and built Bhadra Fort on the east bank of the Sabarmati river


Islam strictly prohibits idol worship and it is forbidden and punishable under Sharia law to worship or give a physical representation or the form of an idol, figure, figurine, animal, etc to God.
Then, how these elaborate filigree carvings exist on pillars and ceilings of this construction ?
The Mosque is built with yellow sandstone, and the complex is centered on a large rectangular courtyard 75 m long and 66 m wide. One enters the court by three entrances, one at the center of each side.
The prayer room is also rectangular and covered by four domes.
In its Indo-Saracenic architecture, the mosque also contains many syncretic elements not necessarily obvious to the viewer: some of the central domes are carved like lotus flowers, closely related to the typical domes of Jain temples; and some of the pillars are carved with the form of a bell hanging on a chain, in reference to the bells that often hang in Hindu temples.
