[The Might]

Then again as mentioned above all great buildings needed such technology.
Simply look at the descriptions of Minas Tirith, the Hornburg or best of all Orthanc. The Gondorians had to have used some advanced technology, probably similar to the Middle Ages way of building cathedrals.

Also look at the palantiri and other works of the Noldor, some that don't even exist in our world.
What I think is also important to keep in mind here is that this kind of advanced technology in M-e is almost always associated with magic.
And it is clear why.
For Men or Dwarves Elvish discoveries might seem works of conjurers rather then scientific discoveries.
Easy to compare it with science in the Middle Ages. Discover something new and you would probably be called a warlock.

Same in M-e. Things such as the Phial of Galadriel or her Mirror surely had certain scientific explanations, I don't know what, but surely there was a way to rationally explain how they worked. But for less educated Silvan Elves or other races they seemed to be magic.

As such most of this truly advanced technology is always present in Tolkien's works, actually quite often... and it is used for good purposes.