Why? What is the significance of this site? This may not be the appropriate place to ask these questions but still. I want to know.
We know little of its history. Apparently at one time, Kevin climbed to its top and using his earthsight-enhanced eyes looked at the Land and the view was good (or maybe not, considering what he did in the end). While this is a nice anecdote, it doesn't explain why we keep returning to this spot. Does Foul hold some special fondness to this place? Perhaps the bird's eye view reminds him of his origins. All those pesky Land-dwellers looks very much like insects from up there. Or does he want to show Covenant (and Linden) that perspective? Or did he learn about Covenant's fear of height and immediately decided to torture him by placing him up there?
The Unbelieving Wikia has this to add:
So Foul wanted,perhaps, to fulfill its ill reputation? Yet do people who don't live next to it believe this or is it just the Mithil Stonedowners? Maybe, the Mithil Stonedowners simply had a touch of prophecy about what will happen to the next Mithil Stonedowner to climb to its top (Lena raped, Triok ravered)After the Ritual of Desecration it became an area of ill omen and is often ignored by the people of Mithil Stonedown.
On another level we have to ask why was it named after Kevin? Kevin did a lot of significant deeds during his long life. There probably aren't that many spots in the Land that he hadn't stood on at one point or another. Yet only this area, along with his famous 7 wards are named after him. Does spending an hour enjoying the view justify naming it after him? I'm also pretty sure Kevin wasn't the only man to climb up there. We see Lena and later Hile Troy and others climb it. I could accept it if this was an ordinary land and Mithil Stonedown, a remote rural village that needed to brag that a famous dude was once there since nothing ever happened there before or after. But this is the Land we're talking about.
To add to this mystery, Kevin's Watch itself must be considered. A jutting cylinder with a flat railed top and steps leading to it isn't exactly a natural feature of the landscape. So it must be either one of two things: A cool feature the Creator put in place so denizens of his Creation could climb up it and be gladdened by the view or an ambitious architectural project someone bold and powerful decided to make for similar if perhaps less wide-reaching goals.
Now the first idea is problematic for several reasons. The first is that this region didn't have originally any such denizens to serve. The current people of the Land are all illegal immigrants from the south while the original denizens of the Land were trees and maybe horses, neither of which could climb steep man-sized steps. The second is that as the story progresses we see its components, like the steps and railing and, on our final visit, the whole shebang, crumble. Now the Creator might not have expected all the disasters his Land went through during these stories but the wearing down of the steps was probably caused by rains and winds hitting it each winter. How then could the steps be navigable when Covenant needs to go down them after all the long eons that passed since this world was created?
So let us consider the second option. The obvious suspect for it would be Kevin himself and such a project was well within his powers in all probability. If we accept it, some things become clearer. As a grand object he created, of course it was named after him just like the Wards were. Kevin's Watch also much have come to symbolize a sin of arrogance in him. He wanted to watch his people from up high. It was, perhaps, his Babel's Tower. Finally, Foul placed Covenant and Linden as a promise to the people of the Land that these people will become Desecrators, just like Kevin and a message to these visitors that they were above these people and their tragedies.
(It's interesting to consider the times people were summoned to the Land in a different spot: Hile Troy and Covenant during Illearth War)
(The fall of Kevin's Watch as a metaphor for E.D. -- I need to write that one.)
