Brooding over the riverbed like a giant beetle, its shell shimmering with translucent mosaic tiles, this ultramodern arts complex, grafted onto the Ciudad de las Artes y las Ciencias, has four auditoriums and enticing levels of plants poking out from under the ceramic exoskeleton. Outside of performance times, you can't enter except by guided visits. These run in Spanish, but there's usually an English summary provided.
For a little extra, you can listen to a rehearsal for half an hour if there's one programmed.