crown, peak, apogee, crest, apex.
Rio summit
peaks...mountain peaks
It is called a summit
The word summit is a noun. Some words that can be used in place of summit are top, crowning point, crest, crown, and zenith. Also on the list are capstone, peak, roof, and pinnacle.
zenith
altitude
The highest point on Mount Everest is just known as the summit.
G8 summit
The summit of the hill
Summit, Top, Zenith, Peak, ......
Dodabetta
The summit of a mountain.