The hidden grove 
TERRITORY OF The Summer Company
The Hidden Grove is a location located behind a destructible wall (mantras like lvl 2 Strong Left will break it) in Summer Isle, consisting of a small cave area, the grove itself, and a singular fountain. (Not to be confused with Greathive Shrines, although they are visually similar.)
When the fountain in the center of the room is interacted with an empty canteen, the player is prompted with "I have nothing to water it with." When interacting with a canteen (any amount of water), around 6 lotuses will spawn around the fountain. The text upon interacting reads "It seems its harvest has blossomed all it can for now." The cooldown for this fountain is currently 60 minutes