Sign Gym

From A KoL Wiki

Sign Gyms are places you can level stats by spending adventures, where the stats gained depend on the current base stat and are uncapped. One can be found in each Moon sign area, for the corresponding stat.

Richard's Redoubt (in Hobopolis Town Square) may also be used to level any stat in exactly the same way as the sign gyms.

Gains from spending one adventure are between (S/10)+2 and (S/5)+5 substats, where S is the base stat being gymmed.

Stats can also be levelled in the same way using the clan gym equipment which may be purchased for the Clan Rumpus Room, but these gains are all capped at quite low levels which make the sign gyms strictly superior for use (in average case) when the stat being gymmed is at least 127.