Haven is the second moon of Cat's Eye, which is a gas giant of 1.3 Jovian masses and the fourth planet in the system of the G2 star, Byers. Radiation from Cat's Eye, not from Byers, makes Haven marginally habitable.
is tidally locked but on the Mercurian, not the Lunar, model;
is smaller than Earth with a thinner atmosphere;
great seismic activity because of its proximity to Cat's Eye,
high rocky mountains,
one almost comfortable valley, Shangri-La, near the equator,
terrestroid biochemistries but dangerous native organisms,
been inhospitable to seeded Terrestrial organisms;
was created by Jerry Pournelle but Poul Anderson wrote one story set there.