U nomenclature (from the IAU and from unofficial sources)

U1 basin (centre of basin at d'Alembert)
U2 basin (centre of basin at Darwin)
U3 basin (centre of basin at Trumpler)
U4 basin (centre of basin at Lacus Temporis)
U5 basin (centre of basin at Olivier)
U6 basin (centre of basin at La Condamine/ Mare Frigoris)
-Maedler- Ukert (and the Lunar V)
Ukert, Rima
-Caes- Ukert, Vallis (the valley SW of Ukert)
-Van Langren- Ulloae (IAU: Taylor)
-Maedler- Ulugh Beigh
-Gassendi- Umbilicus Lunaris (IAU: Tycho and its ray system)
-Gassendi- Umbrosa, Vallis (location unknown)
-Franz- Undarum, Mare
-LTO- Undest, Mons (see link below list)
-Krieger- Ural (see Riphaeus, Montes)
-RP 1097- Urey
-Van Langren- Urselii (IAU: Agrippa)
-NASA- US 1 (or: United States Highway Number One) (Rimae Hypatia) (A-10 / A-11 region)
Usov, Mons
-NASA- Uttermost West (Apollo-15 site)
-Hewelcke- Uxii, Montes (IAU: Lindenau, Rabbi Levi, Zagut, etc.)