Do you know Qutub minar was a "Hindu Mandir"???

It was not built by qutubuddin aibak, but an Astronomer named "Varah Mihir" from Ujjain.

This picture is "Vishnu Stambh" which has Sanskrit inscription on it.

Have a closer look in second picture.

Now look at another pictures clearly depicting ancient Mandir architecture.

You can clearly see "Ashtkon"(eight edged) Piller which has been a part of Ancient Architecture.

Look at this picture, "Yantra" inscribed on the inner wall.

Second picture you see is demolished "Devi Saraswati".

Third picture is again "Devi Saraswati" carved in the walls.

Ref- Praveen Mohan Ji

Pics mostly by @sharo_hit