All 4 Uses

pinnacle
in
The Horse and His Boy
(Auto-generated)

AT first Shasta could see nothing in the valley below him but a sea of mist with a few domes and pinnacles rising from it; but as the light increased and the mist cleared away he saw more and more.†
Chpt 4
Inside the walls the island rose in a hill and every bit of that hill, up to the Tisroc's palace and the great temple of Tash at the top, was completely covered with buildings — terrace above terrace, street above street, zigzag roads or huge flights of steps bordered with orange trees and lemon trees, roofgardens, balconies, deep archways, pillared colonnades, spires, battlements, minarets, pinnacles.†
Chpt 4
To the right there were rocky pinnacles, one or two of them with snow clinging to the ledges.
Chpt 10 *

pinnacles = mountain peaks (the highest points of the mountains)
There would have been a splendid view from the top if it were open ground but among all those trees you could see nothing — only, every now and then, some huge pinnacle of rock above the tree-tops, and an eagle or two wheeling high up in the blue air.†
Chpt 13

Definitions:

(1) (pinnacle)
the highest point -- either literally, like the top of a mountain, or figuratively, like the peak of success or achievement
(2) (meaning too rare to warrant focus)