A ground nozzle is a spray nozzle made for being installed at grade level (i.e. in the ground), usually in cement

Cement

In the most general sense of the word, a cement is a binder, a substance that sets and hardens independently, and can bind other materials together. The word "cement" traces to the Romans, who used the term opus caementicium to describe masonry resembling modern concrete that was made from crushed...

, crumb rubber

Crumb rubber

Crumb rubber is a term usually applied to recycled rubber from automotive and truck scrap tires. During the recycling process steel and fluff is removed leaving tire rubber with a granular consistency. Continued processing with a granulator and/or cracker mill, possibly with the aid of cryogenics...

, rubberized cement, or a similar nonslip surface, or under a grille or similar opening that is flush with ground level.

Ground nozzles are often arranged along walkways, public spaces, in parks, and the like, for architectural decoration, noise masking in urban settings, and as waterplay areas for people to cool off in on hot days.