I have to say the houses were beautiful but as it's the US I was expecting bigger and better. The house are restored to a like new standard and it's good to see it's used, rather than just vacant, most are businesses. You feel like you are walking a private area.
There are signs in front of some houses telling the history of the houses and their previous owner, one was owned by a family that were heavily involved in the property business in Oxnard in the early 1900's with the husband and wife both buying and selling property and land to one another and friends.
There were only two you could enter the restaurant and a wine tasting store that was closed when I was there last Saturday morning. Nice to see if you are passing good and good for a few photos.
Oh it's free, time required not long.

We stumbled on Heritage Square by accident and enjoyed walking around the old houses very much. There are a decent number of signs, and great place to eat, and even wine tasting. I wish more of the homes were open to the public, but the experience was still well worth it.

Nice place to come just to shoot the breeze. It was smaller than what I expected. Strolled around for less than 5 min and just ended up getting somthing to drink at the Dolce Vita restaurant.

Beautiful old buildings repurposed as a wide variety of modern businesses. A few restaurant and wine tasting rooms but mostly dentists, lawyers, and other business offices. I guess they have concerts and other events, and docent-led tours on weekends, but we were there on a quiet Monday to wander on our own.