The Max Lair's entrance is a small, simple cave with people and scientific equipment. The interiors are filled with labyrinthine caves filled with Dynamax Pokémon. At the end of each of these caves is a special Pokémon. Due to the large amount of Galar particles inside the Max Lair, those who enter aren't allowed to use their own Pokémon, but must choose a rental Pokémon that's resistant to the particles' effects.
Peonia can usually be found here. After the player has completed the main story of The Crown Tundra, Peony also appears here, commenting on the special Pokémon the player catches here and being able to be battled once per day. Peonia will sometimes tell the player of a special Pokémon she's discovered at the Max Lair, and tell the player how to find it in exchange for pieces of Dynite Ore. If the offer is accepted, a guaranteed Dynamax Adventure leading to said Pokémon is unlocked. She may also occasionally give the player various Trainer customization items.
- Main article: Dynamax Adventure
Dynamax Adventures are gauntlets of Max Raid Battles the player can take on at the Max Lair with NPC Trainers or other players, allowing the player to catch special Pokémon lurking in the depths of the Max Lair. Initially, these include just Legendary Pokémon, but after obtaining the Legendary Clue? and showing it to Peony, Ultra Beasts will also start appearing. Completing a Dynamax Adventure awards the player with pieces of Dynite Ore, as well as one of the Pokémon they've caught during the Adventure.
Completing three Dynamax Adventures and showing Peony the Legendary Clue? unlocks a mode called "Endless Dynamax Adventure". In this mode, the Adventure does not end until the player is defeated, and the player does not get to keep any of the Pokémon they catch, but the Dynite Ore rewards at the end are bigger than usual.