I've been reading some very basic introductory material on computer hardware and it occurred to me that I would like to take a look at a microchip to see the physical implementation of a simple logic circuit. I found the following image of a 74AHC00 TTL chip, which I understand implements 4 independent NAND gates. I was astonished at how complex the chip appears to be.
(image source zeptobars.com)
The functional diagram of this chip is below, and I think I can see the 4 NAND gates in the die shot as 4 repeated patterns in the centre. Each appears to be composed of hundreds of fine structures. My novice understanding was that NAND gates could be constructed from only 4 transistors, which I thought were elementary components. Clearly my expectations are flawed and I have a lot to learn. So can anyone explain what I am looking at in this image?
(image source NXP datasheet)