The wall retains a generally circular form, but many of its features have been worn away and there is a slight protruding bulge in the western rim.

[1] Like many of the craters on the Moon's near side, it was named (in the Latin form, 'Valtherus') by Giovanni Riccioli, whose 1651 nomenclature system has become standardized.

[2]: 215  Earlier lunar cartographers had given the feature different names: Michael van Langren's 1645 map calls it "Caroli I Reg.

", after King Charles I of England,[2]: 197  and Johannes Hevelius grouped it with Purbach and Regiomontanus as "Mons Libanus" after Mount Lebanon.

[2]: 205 By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Walther.