Less than five miles from our house, Carbon Canyon Regional Park holds a hidden 10-acre grove of approximately 200 coastal Redwood trees.
At the end of a dusty, 1.12-mile nature trail, you'll find the shade of Southern California’s largest grove of coastal redwoods (sequoia sempervirens). Planted in 1975, some have grown to be over 100-feet tall.
Here's a good article with information about the grove:
https://www.hikespeak.com/trails/carbon-canyon-redwood-grove/
And here's another:
https://hikingguy.com/hiking-trails/hiking-orange-county/redwood-grove-hike-guide-carbon-canyon-brea/
And here's the AllTrails link if you like using their app or website:
https://www.alltrails.com/trail/us/california/redwoods-grove