Phleger Estate is a nice little hideway compared to the relatively busy Huddart Park, which is typically where you enter the estate. Park at the Zwierlin trialhead in Huddart Park and follow the Crystal Springs Trail down to the riverbed where you'll see signs leading you to Phleger, part of the GGNRA. Keep an eye out for exotic mushrooms in winter and deer year round. I've also seen a coyote wandering the campground areas and caught a glimpse of a mountain lion on one trip up Lonely Trail.
No need for sunglasses or sunscreen. This trail is well The trail is well-maintained and 95% shaded.