Pal Park (Japanese: パルパーク Pal Park) is a special Pokémon preserve present in the five Generation IV core series games, located at the east end of Route 221 in Sinnoh and in Fuchsia City in place of the Safari Zone in Kanto.
In Diamond, Pearl, and Platinum, players can travel to Pal Park as soon as they have obtained a Pokémon that knows Surf and earned the Relic Badge (DP) or Fen Badge (Pt.) Access will be denied, however, until all the Pokémon in the Sinnoh Pokédex have been seen and the National Pokédex has been obtained.
Yes, there is a Pal Park in Pearl. You need to obtain the Relic Badge, have Pokemon with Surf, and have the National Pokedex in order to access it.