爺ども、命の泉の場所らしいぞ

D12 (Western Temperate)
F7 (Low Desert)
G3 (Central Tundra)
H6 (Low Desert)
M12 (Eastern Temperate)
O7 (Western Tropics)

https://www.gamerevolution.com/guides/485007-atlas-fountain-of-youth-location