We did Gibraltar earlier this year, the cable car I can see being useful there, I did treck up to the top of the rock to see my monkey relatives one day and cable car another. It sure was a long walk !!!!!
The Castle though you can walk in 5 minutes or so and I don't see the usage would pay for itself !
Plus they close the Keep when the wind gets any more than a breeze so I would have to see how often a cable car would be closed
