I would count colossus of bletchley park as the first computer, some may debate that earlier devices were also computers a few years before it. A few say that later devices were the first computers because colossus was not purely electronic, but mainly the idea that later devices were the first computers is because colossus was classified until many decades after the war, so only the few who had worked with it knew about it.
Bletchley is now a museum, it's countryside location has been engulfed by the town Milton keynes growing around it, a rebuild of colossus and other wartime equipment is on show there and are sometimes run for demonstrations of how the originals were used.
As for earlier devices with computer-like properties one interesting one which you could say was the first "robot" was the governor device on steam engines (centrifugal governor) this was an ingenious little thing developed by James watt for keeping steam engines from going out of control without need for a human monitoring them. This system was perhaps one of the first to use a negative feedback loop, this way if the engine (we're talking mills and water pumps here not trains) ran too fast or too slow the heavy balls on the arms would rise or drop under "centrifugal force" and thereby lift into place or drop out of place a valve which cut off the supply to the steam engine so that it would be regulated. Really simple but very clever and elegant.
Edited by rp88, 21 April 2016 - 01:52 PM.
Back on this site, for a while anyway, been so busy the last year.
My systems:2 laptops, intel i3 processors, windows 8.1 installed on the hard-drive and linux mint 17.3 MATE installed to USB