On our way out of the Sol Duc area, driving back towards Lake Crescent, we decided to hike this short loop trail. If you are driving towards Lake Crescent, you will not see the sign for Ancient Groves, there's only a sign if you are coming the other way/entering sol Duc.
The parking is a wide pull out on the side of the road. There is a sign at the start of the loop titled "National Treasure", then once you enter, there is another sign that points you in the direction of the Loop. Lot of old growth trees, giant ferns, and nursery logs with lots of new baby trees growing on them.
Easy kid friendly hike!