Mare Tyrrhenum
What Mare Tyrrhenum is
Mare Tyrrhenum is an albedo feature — a region named for how bright or dark it appears from a distance — on Mars, centred at 19.8° S, 105.0° E in the Mare Tyrrhenum quadrangle.
Where the name comes from
Tyrrhenian Sea, between Italy and Sicily. The International Astronomical Union approved the name in 1958.
What it would take to settle Mare Tyrrhenum
Mars scores 26.6 as a world. That number is the same for every square metre of it — but sunlight, water, radiation and the ground under your feet are not. This is the same question asked at 19.8° S, 105.0° E.
What this spot has going for it is sunlight — 95% of the sunlight the sunniest latitude on Mars gets. What works against it is water — outside the ice-bearing latitudes.
Computed from Mare Tyrrhenum's catalogued latitude, longitude and feature class — 74% of the model's weight had a basis here, and 2 axes were dropped as not applicable to Mars (radiation geometry, earth link). Gravity, pressure, delta-v and distance from the Sun are the same everywhere on Mars and are already counted in the world's own index, not again here.
What this cannot see: elevation. Slope, local shadowing and the polar “peaks of eternal light” — ridge tops near the poles of a barely tilted world that catch sun almost continuously while a crater floor kilometres away never does — need a terrain model this does not have. Where a real mission targets a pole, that is usually why.