These trees look like a compact form of London Plane.
That's because they are!
London Plane (Platanus x acerifolia) is a hybrid of Sycamore (Platanus occidentalis) and Oriental Plane (Platanus orientalis).
The Sycamore has great form but is highly vulnerable to anthracnose (a fungus).
Oriental Plane has less useful form but is highly resistant to anthracnose.
Hybridize the two and you get a handsome tree (London Plane*) that is disease-resistant.
|American Sycamore trees - Long Island, New York|
* It probably should be called Spanish Plane as that is where the hybrid is thought to have first appeared. It's called London Plane because it got used so widely there before everyone else cottoned-on and started using it too.