A Polish architect by the name of Krysztof Kotala has released designs for an audacious project with his design firm, 8+8 Concept Studio: a tennis facility located entirely underwater just off the coast of Dubai, where spectators could choose to watch the games below them, or the sea life above them through a massive glass dome.

8+8 Concept Studio

Why Dubai? Well, Kotala says, “[The court] should be something where there is the tradition of tennis. Dubai is perfect for this idea.”

Dubai, which is notorious for superlative construction, is already home to the world’s highest tennis court, atop the Burj al Arab skyscraper. The proposed location for Kotala’s’s project (probably one of the world’s lowest tennis courts) is just next door:

8+8 Concept Studio

Of course, it’s worth noting that this design, for now, is just a concept. There are no plans to build such a structure, and actually doing so would require confronting massive engineering challenges and astronomical costs. The architectural blog Archpaper noted that the design would require a glass pane at least 108 feet wide—several times larger than the 32-foot-pane standard in manufacturing. Building a curved sheet of glass of that size, as depicted in the renderings, is unprecedented.