El Raval is part of Barcelona's old city, and was walled in as an extension of the medieval town. It remained mostly fields and shipyards until the 1850s brought the industrial revolution to the city. People swarmed in from the countryside for jobs at new factories. Soon it became the most densely populated area in Barcelona. 

For many years, the neighborhood was known as a "ghetto" for new immigrants, a stopping point for sailors, and an area plagued with brothels. It was considered to be the Red-Light District of Barcelona. Thankfully, the city has worked hard to clean up the Raval. Better street lighting has been put in, slums were removed to build the Rambla de Raval, and the MACBA museum complex (along with the CCCB - Contemporary Culture Center of Barcelona) was built as part of the gentrification effort.

Universities, museums, and 5 star hotels have moved in and changed the feel of Raval. Nowadays, the barrio is vibrant, historic, authentic, and full of personality. The Raval is very different than it was 20 years ago, but if you pay attention you can still see the two sides of this historical neighborhood. 

Again, please be safe if you plan to visit El Raval, especially at night. Despite its charm, it is a barrio known for pickpocketers, so always keep an eye on your belongings and stick with a friend.