Park Guell
This is Gaudi's iconic park. Had AlteCocker been smart, she would have had a reservation. She was not smart. She set off at the crack of dawn expecting to have to queue, but, if you get to the park before 8:00am, there are no tickets and you walk write in. Beginners luck--or something like that. Park Guell is a steep uphill climb. AlteCocker does not regret taking a taxi there. She walked to the Metro after her visit. No problem going downhill.