Hands down my favorite part of San Juan
The Reservation features the no-longer-in-use lighthouse structure, trails, coastal and beach elements, and the Cattle point Interpretive Area. Very pleasant for a causal adventure on foot.
We spent a few quiet hours here. We timed the visit to low tide to explore the tide pools. The kids enjoyed the pools and also the exploration of the rocky beach, up to the lighthouse (even better views up there), then back to the parking lot then down to the beach for an hour or so. There is no fee box here so we bought the Discover Pass on our cell phone to cover the parking. If we were correct it looks like there is great cliff hiking up the hill even further. This is a good place for a slow afternoon. The views are outstanding.
Scenic views and some cool places to explore. Not much to do other than observe the nature around you, so if that's not your thing this one might be worth a miss. However, the views of the Olympic Peninsula is really cool, and you can see quite a few of the Cascades. If you're lucky, you'll even catch an eagle hanging around!
Fantastic views of the ocean.