Catalan Way, also known as The Catalan Way towards Independence, was a 400-kilometre (250 mi) human chain in support of Catalan independence. It was organized by the Assemblea Nacional Catalana (ANC), and took place in Catalonia on 11 September 2013, which is the National Day of Catalonia. Catalonia's Department of the Interior estimated the number of participants at about 1.6 million.
The protest was supported by 14 nongovernmental groups. The human chain followed the ancient Via Augusta, from El Pertús (Vallespir) up to Alcanar (Montsià). According to Carme Forcadell, president of the ANC, it was "a symbol of the unity of Catalan people to achieve national sovereignty"...Further details at the Wikipedia link. There are an abundance of relevant videos at YouTube; I thought the one embedded at the top was the best. This was a promotional video:
And this one focuses on the activities around the Sagrada Familia in Barcelona:
I suspect my cousin Karl is in one of those human chains.