One Day In Tangier
If you find yourself at the southern tip of Spain it is very simple to catch a ferry over to Morocco, the ride over only takes about an hour. We went over for a day trip, but one could easily use Tangier as a jumping off point for a longer Moroccan vacation.
To be honest, Tangier seems like a city that has completely lost its relevance. Every place we visited had its glory day in the 1970's. Younger generations might not respond well to names like Elizabeth Taylor, Tennessee Williams and Malcolm Forbes--even the US consulate has closed its location here. The city (or its guides) would do well to move on from these American and European encounters of the past and focus on its unique history, customs and architecture.
If all you want to do is check the box to say, "been there" a day wandering through Tangier is enough, but to really get a feel for the country I'd recommend going to Marrakesh or Fez and plan to spend one night in the desert.
From Tarifa you can buy ferry tickets right at the port for about €65 roundtrip. We found that the que for the afternoon ferry back to Tarifa can be quite long. We arrived one hour before sail time and barely made it onto the ship. We arranged for a private guide using a Rick Steves' recommendation. The all day private tour cost us €110 and while the tour was very interesting, I wasn't super impressed with our guide.