Award winning design on site of the church that’s taken over a century to build. The numbers on the placard correspond to audio clips that visitors can access on a headset provided at the entrance (for a fee). The tour is marked by a series of checkpoints that give detailed information about that section of the church. The tour is enhanced by an audio guide, but these placard augment the experience of visitors who don’t have an audio guide as well. See the whole project by Spanish firm Virgili here.