There are tours available for the largest building in the world (by volume) https://www.boeingfutureofflight.com/tour https://www.boeingfutureofflight.com/tour

There are tours available for the largest building in the world (by volume) https://www.boeingfutureofflight.com/tour https://www.boeingfutureofflight.com/tour The height is nothing much, but the main factory is 2,607 ft (794 m) along the longest dimension.