This is dharahara tower. It was first build in 1832
by muktiyar(equivalent to prime minister). It has a height of 61.88 meters.
Bhimsen Thapa under the commission of Queen Lalit Tripura Sundari and was a part of the architecture of Kathmandu recognized by UNESCO.
It was destroyed by earthquake 25,april 2015(stump of base remain).
Thankyou 
Thank you .