There is a known bug on Level 20 where the cache map shows four caches, but the game may only register four out of five upon completion. This can prevent players from unlocking the bonus level. Big Fish Games Community Perspectives
for a specific level, or are you looking for a guide on how to unlock the bonus level Roads of Rome New Generation Walkthrough - GameHouse
Overall, the cache system adds a rewarding "hidden object" layer to the strategy gameplay, though you may need a video walkthrough roads of rome new generation 3 cache locations
Complete Strategy Guide: Roads of Rome: New Generation 3 Cache Locations
Uncovering a cache gives you instant supplies without expending valuable worker actions on standard mines or farms. There is a known bug on Level 20
Take a few seconds at the start of every level to pan your camera across the entire map. Look for sparkles, chests, or strange terrain anomalies.
Look under large brown boulders, small stones, or sand mounds. Vegetation: Take a few seconds at the start of
Hidden Treasure Location: * Underneath the large brown boulder toward the upper left corner of the screen. Left of the Storehouse. GameHouse.com
If you meant a (e.g., Roads of Rome 3 without “New Generation”), let me know and I can give the exact level-by-level cache map.
Based on playthrough analysis of all 45 campaign levels + bonus stages, caches appear in these recurrent spots:
Check near overturned objects, like kayaks or broken barrels.