I've been running a lot for over two years now. Mostly along the bay and in neighborhood streets, both in the East Bay and in the peninsula. A couple times along beaches (Ocean beach and Point Reyes). It clears your head.
I changed it up today and went running on one of my favorite hiking trails in the Santa Cruz mountains off Skyline Rd (Blvd?). And no music and no timing. Much more refreshing, and a lot more green to see. And it was a lot more fun---about the running and not some goal. Although I ran out of breath a few times going uphill at altitude, I felt far better afterward than when running on flat ground, which I've been getting bored with.
But I need better shoes for this.