Something I noticed about every natural ”Shardpool” perpendicularity: (meaning every perpendicularity that was not placed or moved)
They are ALL in the mountains.
On Roshar: Cultivation’s perpendicularity is in the Horneater peaks.
On Sel: the only Shardpool we see is up in the Aonic mountains.
On First of the sun: Patji’s eye, at the very top of the Island.
On Scadrial: During Alendi’s time, Both the Well of Ascension and Ruin’s Shardpool (the dark lake that someone tried to take a sample of, but was stabbed by the Mist Spirit.)
During Era 1, the Well was placed intentionally placed in Luthadel. The Pits of Hathsin, I think might have also been intentionally placed, and they aren’t really a “Shardpool.” I also don’t have a very intimate knowledge of the geography around the Pits, so I don’t know if they are in a terrain that could be called “mountainous.” (All that to say I don’t know whether or not it counts.)
During Era 2, the perpendicularity is the blue mountain spring that is mentioned in the Broadsheets.
On Nalthis and Taldain, we haven’t seen the perpendicularity, but we also haven’t seen any long walks through the mountains...
Anybody else notice this pattern, or have any idea as to why that is?