I was born in Spain and lived there for 22 years (now I’m a proud US citizen), so I am familiar with the Gibraltar issue. I have always believed that Spain’s position is extremely hypocritical. As long as Spain holds on to Ceuta and Melilla on Morocco’s coast, she does not have the right to complain about Gibraltar.
I was in Spain for a two week visit in 1991. We travelled south from Madrid to Algeciras and around Spain to Barcelona, and finally back to Madrid on a Spanish Rail Pass. We took a boat across from Algeciras to Tangier, and then took a bus from Algeciras to Gibraltar. We had breakfast on Gibraltar, a full English breakfast - a real treat after a week in Spain. I climbed the Mediterranean Steps to the top...an exciting, and for me a rather strenuous climb. The climb was well worth it (my wife took the less strenuous roadway to the top).
At the top it quickly becomes obvious what a military advantage Gibraltar was for the British. We could also look down on the naval docks below, where the Ark Royal (Jump jet version) was in port. They have guns on top that were capable of hitting anything passing them between Gibraltar and Africa there at the mouth of the Mediterranean.