How to tell if GKE Cluster is Zonal or Regional cluster?

How do I tell if an existing cluster’s type is zonal or regional?
I understand when I create one, I can define it to be single zone, multi zonal or regional and understand these can’t be changed after creation but would be good to know what type an existing cluster is.

Cluster information:

Kubernetes version:
Cloud being used: GCP

Regional cluster’s will not have a sub-zone included in the location string text. For example, this can be seen in the UI:

image

As well as the CLI:

gcloud container clusters list --format="value[separator=' → '](name,location)"
regional-cluster-1 → us-central1
zonal-cluster-1 → us-central1-c

us-central1 indicates regional (no sub zone) and us-central1-c indicates zonal (zone c).

You could even look deeper at the nodePools using something like:

gcloud container clusters list --format="value[separator=' → '](name,location,nodePools.selfLink)"
regional-cluster-1 → us-central1 → https://container.googleapis.com/v1/projects/.../locations/us-central1/clusters/.../nodePools/default-pool
zonal-cluster-1 → us-central1-c → https://container.googleapis.com/v1/projects/.../zones/us-central1-c/clusters/.../nodePools/default-pool

/v1/projects/.../locations/ = regional
/v1/projects/.../zones/ = zonal