Apexes, noun plural of apex. Synonyms in the same form.
Zenith
zeniths, peaks, acmes, pinnacles, crowns, heights, culminations, points, apotheoses, crests, apogees, climaxes, maximums, extremes, primes, meridians, capstones, superlatives, culmens, noontides, elevations
Summit
tops, summits, ends
Other
vertexes, tips
All synonyms for apex →