We slept in caves in storm; in the lee of icebergs in strong winds and on the mossy cushions of earth Concavities.
"My Attainment of the Pole"
Frederick A. Cook
Many of these natural Concavities are of considerable size-having a superficial extent of several hundreds of acres.
"The White Gauntlet"
Mayne Reid
In the face of this stone wall are three Concavities - fireplaces over which cooking pots are placed.
"The Bontoc Igorot"
Albert Ernest Jenks