Barcelona-based artist Jaume Plensa said the first thing he does after checking into his hotel during stays in Chicago is drop by Crown Fountain, the digital waterwork that features human faces spitting water, just to make sure his popular downtown installation really exists.

“Sometimes I think it was just a beautiful dream I had 10 years ago,” Plensa said at a press conference Tuesday. Millennium Park, which turns ten years old in 2014, counts Plensa’s whimsical fountains among its more popular installations. A new piece of his, on loan from the artist through the end of 2015, attempts to build on that momentum.

Entitled 1004 Portraits, the new installation features three cast-iron heads some 20–23 feet tall, their tranquil expressions facing west toward Crown Fountain and Michigan Avenue. Walk around the visages, though, and their volume drops away—the figures, all portraits of young girls with their eyes closed, are warped and stretched along their vertical axes. Their names are Laura, Paula, and Ines.

A fourth head—this one 39 feet tall, bleach-white, and made of resin—watches over the entrance of Millennium Park at Madison Street and Michigan Avenue. That piece is entitled, Look Into My Dreams, Awilda. (The other 1,000 portraits referenced in Plensa’s title refer to the LED projections that cycle through as the backdrop for Crown Fountain.)

“I invite everyone in Chicago to dream with me and with my heads in Millennium Park,” said Plensa.