Everything

The two natural wonders stack up quite differently when looking at why they are so unique:

The Quirks of Uranus

The Sideways Tilt: Uranus spins on its side with a 97.77° axial tilt, meaning its poles point directly at the Sun, leading to 21 years of continuous daylight and 21 years of pitch-black winter.

The Ice Giant: It is largely composed of flowing icy materials like water, ammonia, and methane over a small rocky core.

Lopsided Magnetosphere: Its magnetic field is tipped over by nearly 60° and is wildly offset from the planet's center.

Strange Moons: Recent studies reveal its moons may actually contain huge subsurface oceans. 

The Wonders of Uluru

A Sandstone Monolith: Uluru is a massive 348-meter-tall chunk of arkose sandstone (a 600-million-year-old geological inselberg).

Vertical Layers: Originally formed underwater, tectonic shifts pushed this massive rock's strata to stand nearly 90° on their side.