This triangular neighbourhood is the very first urban planning project in Europe. It was built in the 18th century for the residents of the Ribera quarter who had to move because of the construction of the Ciutadella of Barcelona. Until then, it was inhabited only by a few local fishermen.
You should definitely not miss Barceloneta Beach - the liveliest beach in Barcelona - as well as have some drinks and original tapas or paella in bars along the beach. This neighbourhood never sleeps, no matter when you choose to visit it. It always has something remarkable to offer.
Wikipedia https://en.wikipedia.org/wiki/La_Barceloneta,_Barcelona
Info http://www.barcelonaturisme.com/wv3/en/page/378/la-barceloneta.html
Coordinates 41°22'50.352" N 2°11'23.739" E