If you were dreaming of a park, it could mean you experienced nostalgia for a park. During the day, you might have been reminded of old memories about a park. This reminder may have triggered a dream about a park.
If the park holds other special memories for you, then you might be more inclined to dream about this place.
Prompt for 3TC for Aug. 19 2019 is “park, gallop, licorice“.