You never get to know the true name of things until people christen them. In this case, for obvious reasons.
The Design Museum is located on Plaza de las Glorias, a place that was to be the centre of the Ensanche as there intersect the Diagonal, the Meridiana and the Gran Vía, but in fact became a freeway exchange. In 1992 the Olympics led to a new design of the exchange, with trees inside, but it still is that. Nowadays, and after many proposals, a project to bury traffic is underway, transforming the square into a large park, according to the following image.
The Design Museum is on the southeast flank of the new square, on the axis of the Avila street. The difference of level between the new square and the street have led the authors, MBM, to have a ground floor with escalators open to the public. This is a confuse part of the building, that in itself has become one more piece of the strange objects populating the square, as the Agbar tower or the Mercat dels Encants.