Pokémon Land is an anime location in Pokémon: Indigo League.
Pokémon land was an attraction park in the Kanto region which contained many different robotic Pokémon ten times their natural size. It was run by Team Rocket leader Giovanni, who spent billions to build it.
Ash, Misty, Brock and Team Rocket were once stranded on Pokémon Land after a group of Gyarados flung them their with their Dragon Rage, unaware it was an attraction. Ash's and Team Rocket's Pokémon were separated from their trainers, but reunited when they were riding on a cart, which crashed into many of the mechanical Pokémon and destroyed the entire attraction instantly, much to Giovanni's anger.
Although the Pokémon were mechanical, they tried to attack Ash and the others for unknown reasons. It most likely was due to their functionality as part of the attraction and Ash, his gang, Team Rocket and the Pokémon were likely in the areas where they should not have been, as Jessie and James ran into a Keep Out sign while trying to evade a mechanical Moltres.