Shah Jahan is said to have planned a second Taj Mahal.
What was it supposed to look like?

Question

Accepted Answer

An identical black-marble Taj Mahal across the river, as his own mausoleum. — Never built. He was imprisoned by his son Aurangzeb before construction began. Foundations of the 'Black Taj' theory are still archaeologically debated.

Shah Jahan is said to have planned a second Taj Mahal. What was it supposed to look like?