As an ex-Barcelona expat, now living in Buenos Aires, I always thought that the city of Gaudi didn't have any secrets anymore for me to uncover. I was wrong... I've just returned from a business trip to Barcelona where I decided to join the Sunday morning walking tour of Walkabout Barcelona and discovered a hidden Barcelona gem. This company organises walking-, horse riding-, bike- and nordic walking tours in the Collserola Park, the largest green area of the city. The park is situated in the Collserola hills, with the famous Tibidabo as the highest point, and offers amazing views over the city, the sea, the airport and Montserrat. The funniest part of the tour was the visit to the highest viewing point of the city: the communication tower built by Norman Foster and the little funicular railway that brought us back to the centre of town.