The thing that stood out about this guided walk in comparison to other guided tours was that our guide Ricardo was an architect himself with a depth of knowledge and passion for his subject that could not be matched by the typical guide.
The walk took 3 hours and covered the development of Gaudi's practice and its relationship to the rebuilding of the city from the late 19th to early 20th century. My wife uses a walking stick and we were a bit concerned about keeping up but the walk was well paced with some opportunities to sit and rest while Ricardo talked about various buildings and their relationships to the surrounding architecture.
Overall great value and the perfect start to a Barcelona visit.