SAMARANGANA SUTRADHARA is an encyclopedic work on classical Indian architecture (Vastu Shastra) written by Paramara King Bhoja of Dhar (1000-1055 AD).

In 83 chapters, subjects treated are town planning, house architecture, temple architecture and sculptural arts together with Mudras (the different hand poses and the poses of the body as well as the postures of legs), the canons of painting, and a chapter on the art of mechanical contrivances, the yantras (chapter 31).

This chapter on yantras has attracted the attention of pseudoscience and ufology in particular.[1] Verses 95-100 mentions bird-shaped aerial cars (Vimanas), and verses 101-107 mention a sort of robots acting as guards.

Here are some verses from Samarangana Sutradhara, which describes characteristics a "sthapati" i.e. architect (based on translation by Punya Mishra).

-The architect should be well-versed in the science involving the significance of objects to be created and their specificationss. He should know the theory and the practice; he should have the insight and the skill accompanied with procedure.
-That person is said to be an expert in workmanship who knows how to sketch the ground plan, draftsmanship, the horizontal and vertical measurements, the details of ground work of the plot, the 14 kinds of sketch lines, the cutting of the logs and stones etc., and seven kinds of circular sections; well finished joinings of the joints and proper demarcation of upper, lower and outer lines.
-A sthapati should know eightfold workmanship, the draftsmanship and sketches of various kinds, and variety of carpentery, stone-masonry and gold-smithy. The engineer equipped with these merits invokes respect. One who knows the fourfold engineering with its eight constituents and who is pure in his mind gets status in the assembly of engineers, and is endowed with a long life.

- Wiki

"European scholarship regards human civilization as a recent progression starting yesterday with the Fiji islander, and ending today with Rockefeller, conceiving ancient culture as necessarily half savage culture." It is a superstition of modern thought that the march of knowledge has always been linear." "Our vision of "prehistory" is terribly inadequate. We have not yet rid our minds from the hold of a one-and-only God or one-and-only Book, and now a one-and-only Science."~ wrote Shri Aurobindo Ghosh (1872-1950) :

http://www.cincinnatitemple.com/articles/ScienceVimanas.pdf

A STUDY OF VARIOUS ASPECTS OF TOWN PLANNING OF THE VIJAYANAGAR CAPITAL :

http://www.scribd.com/doc/31466188/A-STUDY-OF-VARIOUS-ASPECTS-OF-TOWN-PLANNING-OF-THE-VIJAYANAGAR-CAPITAL

Corrosion resistance of the Dhar iron pillar :

http://home.iitk.ac.in/~bala/journalpaper/journal/journalpaper_34.pdf

Vimanas: Ancient Indian Flying Machines, UFOs, or Sanskrit Sci-fi?

http://heritage-key.com/world/vimanas-ancient-indian-flying-machines-ufos-or-sanskrit-sci-fi

Ship Building :

http://www.new.dli.ernet.in/rawdataupload/upload/insa/INSA_1/20005af4_137.pdf

The Concept of Yantra :

http://www.new.dli.ernet.in/rawdataupload/upload/insa/INSA_1/20005abd_118.pdf