Union Cave

19 species to catch in 3 areas of this location, across 5 game versions.

Data from Pokemon Crystal only: exact levels and the encounter rate for each Pokémon.

in tall grass

Conditional slots 22 for 9 species — time of day, weather, radio and other switches

The game keeps these slots separate from the base ones. Condition sets exclude each other (it cannot be morning and night at once), and the source does not say whether a condition adds a slot or replaces the whole table — so we list them row by row instead of adding them to the rate on the tile.

Pokémon	Conditions	Level	Rate
Rattata	at night	4–8	49%
	during the day	4–8	19%
	in the morning	4–8	19%
Raticate	during the day	21	10%
	in the morning	21	10%
	at night	21	10%
Sandshrew	during the day	6	30%
	in the morning	6	30%
Zubat	during the day	5–22	100%
	in the morning	5–22	100%
	at night	6–22	65%
Golbat	during the day	22	30%
	in the morning	22	30%
	at night	22	30%
Geodude	during the day	6–20	65%
	in the morning	6–20	65%
	at night	6–20	65%
Onix	at night	6–23	18%
	during the day	6–23	18%
	in the morning	6–23	18%
Wooper	at night	5–8	40%
Quagsire	at night	22	20%

while surfing (Surf)

with the Good Rod

Conditional slots 9 for 4 species — time of day, weather, radio and other switches

The game keeps these slots separate from the base ones. Condition sets exclude each other (it cannot be morning and night at once), and the source does not say whether a condition adds a slot or replaces the whole table — so we list them row by row instead of adding them to the rate on the tile.

Pokémon	Conditions	Level	Rate
Krabby	during the day	20	35%
	at night	20	35%
	in the morning	20	35%
Staryu	at night	20	10%
Magikarp	during the day	20	35%
	in the morning	20	35%
	at night	20	35%
Corsola	during the day	20	10%
	in the morning	20	10%

with the Old Rod

with the Super Rod

Conditional slots 9 for 4 species — time of day, weather, radio and other switches

The game keeps these slots separate from the base ones. Condition sets exclude each other (it cannot be morning and night at once), and the source does not say whether a condition adds a slot or replaces the whole table — so we list them row by row instead of adding them to the rate on the tile.

Pokémon	Conditions	Level	Rate
Krabby	during the day	40	40%
	in the morning	40	40%
	at night	40	40%
Kingler	during the day	40	10%
	in the morning	40	10%
	at night	40	10%
Staryu	at night	40	30%
Corsola	during the day	40	30%
	in the morning	40	30%

static, set by the game

Conditional slots 1 for 1 species — time of day, weather, radio and other switches

The game keeps these slots separate from the base ones. Condition sets exclude each other (it cannot be morning and night at once), and the source does not say whether a condition adds a slot or replaces the whole table — so we list them row by row instead of adding them to the rate on the tile.

Pokémon	Conditions	Level	Rate
Lapras	day of the week: Friday	20	100%

The red marker is Union Cave. A diagram, not a world map — distances are not to scale, but directions and connections match the game. The legend below the drawing explains each symbol.

• Route — number inside
• Sea route — Surf only
• City
• Interior — cave, forest, tower; placed next to its entrance
• Path between places
• Path that requires Surf
• Entrance to an interior — not a passage to the other side