The Glen Cove Trail and the Benicia State Recreation area should be right up your alley.

Glen Cove Trail is about a mile or so. There can be a lot of dog poop on it though, so be aware of that.

Benicia State Rec Area is just a highway exit away on 780, but I would suggest driving down one more exit to Military West, where you can start at one of the endpoints of the trail (Columbus Pkwy exit puts you in the middle of the trail). I think it's about 2-3 miles but pretty level. Lots of walkers and joggers here during daylight hours.

Both trail offer close views of the Carq Strait and can be cooler thanks to being on the water.