Gymboree Come To Gymboree’s Sweetheart Party Open House On Saturday (Sponsored) Photo via GymboreeDuring this season of love, Gymboree brings its most spectacular friendship-fest to Park Slope/Gowanus families with young children ages 0-5 on Valentine’s Day, this Saturday, February 14 between 10am and 1pm. This sparkling new Gymboree learning center is an amazing asset to the Park Slope community.