Radnor Lake is a really nice small park. The park is very well maintained and well used.
To the best of my knowledge it has the highest elevations in a Nashville area park with the highest point in the park being on the Ganier Ridge Trail. Nashville just doesn’t have tall mountain areas so this is a nice change.
If I have a complaint at all about Radnor it is that it is so well used that it’s almost crowded. This is especially true on the flatter trails around the lake itself. I usually like to walk by myself to get away from people so crowded trails just are not my thing. The two times that I have been to Radnor Lake the parking lots were near capacity. The park itself makes up for this one small defect brought on undoubtedly by the park's own enjoyability.
Radnor Lake is worth the trip.
The official park web site can be found here.
The Friends of Radnor Lake site is here.
The best trailmap with contour lines is available here.
A simple map wihtout countour lines is avaiable here and here.