The family headed to Coldwater Canyon Park on Tuesday (27 August) and Luca had a great time playing on the swings, tossing a ball around and whizzing down the slides.
The former Lizzie McGuire star dressed down in black shorts, wearing a navy blue top and felt hat. Her blonde hair looked sleek and she sported minimal make-up, wearing a slick of red lipstick.
Hilary and Mike, who recently celebrated their third wedding anniversary, looked like proud parents as they watched Luca play in the sandpit with a ball.
One-year-old Luca, who had the full attention of both parents, looked incredibly cute in a blue cap, long-sleeve printed shirt, stripe shorts and a pair of Converse, as he held onto a large beach ball.
During a go on one of the slides, Hilary even made sure to get her phone out to capture Luca sliding down!
Earlier this month, Hilary confirmed plans to return to music to work on a follow-up to her 2007 release Dignity. And in a Twitter Q&A this week, the star shed some more light on her future plans.
She told one fan: "I'm exploring a lot of cool options & don't want to give a timeline yet but I promise exciting stuff is coming."
There was another reason for Hilary to celebrate this week, as it was 10 years since the release of her first album, Metamorphosis.
Taking to Twitter, she said: "Thanks for all the love! I hope to make you guys proud with the next 10 years! big smooch xx."