This formation is known as "The Dalles," sometimes improperly styled "dells."
Now many were the hills and dells haunted by the fairy folk.
The Indians also told of the imps that haunted their dells, luring the hunters to places of peril.
We are delighted to hear that your little folks like the dells.
Ven you dells me 'I ax your humble parding'—den I let you up!
I am the same Œnone whom thou didst woo in the dells of woody Ida.
They soon lost the sound in the intricacies of cliffs and dells, and never again found that stream.
It is located on the left at the entrance to the wild grandeur of the dells.
The light of the sun must rest on the hill-side long before it reaches the dells beneath.
It was a golden evening when he rode into the dells of Vallombrosa.
Old English dell "dell, hollow, dale" (perhaps lost and then borrowed in Middle English from cognate Middle Dutch/Middle Low German delle), from Proto-Germanic *daljo (cf. German Delle "dent, depression," Gothic ib-dalja "slope of a mountain"); related to dale (q.v.).
rogue's cant 16c.-17c. for "a young girl of the vagrant class," of uncertain origin.
A Dell is a yonge wenche, able for generation, and not yet knowen or broken by the vpright man. ... [W]hen they have beene lyen with all by the vpright man then they be Doxes, and no Dells. [Thomas Harman, "A Caveat or Warning for Common Cursitors," 1567]