Chicago got a new beach this season. It doesn't even have an official name yet. It's "the new beach around 39th Street". It's easily accessed from the Lakefront Bike Trail - but we didn't see any nearby parking.
I don't know the purpose of this mat that led down to the water. It looked, to me, like they had rolled out a blue carpet to welcome the beachgoers. (It's a beach - so it gets a blue carpet instead of a red carpet.) It was empty (especially for a nice Sunday morning) but probably will be a little more used as it gets discovered.