How do humans perceive height or vertical drop? I'm looking at this video: Neil Burgess: How your brain tells you where you are, which discusses neurons within the brain that help people remember where stuff is in relation to other objects.

I'm interested if there are similar kinds of neurons or areas of the brain that are specifically involved in recognizing heights. For example, I can be looking at a flat suface across horizontal distance and I feel fine (for example looking at a distant building). But if I'm looking at another flat surface, of the same distance, but straight down, I may feel uneasy. This feeling of unease tells me that an additional mechanism may be involved in perceiving heights. 

The question is - what part of the brain can differentiate horizontal distance from vertical drop?
The answer that I recently discovered is that humans have a number of mental adaptations to environmental challenges, as described by Evolutionary Psychology. 

For example, This TED talk on beauty describes how most "beautiful" landscape paintings share common traits, like looking down a valley with wildlife, a water source AND gravitational advantage (as if looking down from a tree).

The explanation given is that gravitational advantage (being higher) helps evade predators and spot them as they approach. 

From looking at these adaptations, it appears that there's neural circuits in the human brain which can recognize height and prefer it in some amount (as in sitting in a tree), but feel aversion towards it in greater amounts (staring down a cliff).