HT Lines

The average person doesn't need to know, if this is for a job ask the lines company or power company (whoever owns or operates the lines) where the substation is.

Alternatively, look around the local area or try looking at Google maps or something.

You don't say where you are, are you sure you are looking for a substation and not just a 11kV distribution transformer?

What are you trying to accomplish?

To see the 11kV line look overhead or dig the surround near a 11 Kv substation for underground cables. Follow the cable until it reach the grid station.

or dig the surround near a 11 Kv substation for underground cables

Or not.

If you have the authority to dig then you have the authority to obtain the relevant substation drawings, or at the very least hire high voltage cable tracing gear, which is a lot easier, cheaper and safer.

_{Jack - Has actually worked on grid networks and in substations.}

Call your local power utility power department and I am sure they should know where is the grid station.