Castle Montjuic is accessible by car, by monorail from the Metro, and by convenient drop-off stop from the Hop-on-hop-off (HOHO) bus.
We chose to ride the teleferic (sky lift) to the castle from the HOHO drop off. One, it is a pretty long walk to the top for people who have already marathon-walked for the day, and two, who doesn’t like the thrill of a sky lift?
The Castle was closed for tours when we arrived; however, the grounds remain open much longer. 
The view from the castle grounds included the harbor area
and Barcelona city. Notice Sagrada Familia. It looks like stalagmites rising above the skyline.
We decided not to re-board the HOHO from here. We took the monorail (included in our Metro T-10 pass) to the Metro Paral-el station and changed trains to our usual stop at the Liceau station on La Rambla.
One more Gelato break at a shop just off the Placa Reiel. Two scoops – dark chocolate and caramel. Yum!
Tomorrow, we board the Carnival Vista for a Mediterranean cruise.
Next post to come: Stop #1 Marsailles/Provence