At which Los Angeles studio did Metallica begin recording its self-titled 1991 album?

Metallica began recording its self-titled 1991 album at One on One Recording Studios in Los Angeles.

The main recording sessions started in October 1990 and continued for much of the following year. The band also spent about a week at Little Mountain Sound Studios in Vancouver, while final overdubs and mixing took place at A&M Studios in Hollywood.

One on One was therefore the principal starting point, but it was not the only studio associated with the album. This distinction matters because several studios appear in accounts of the record's production.

The sessions were led by producer Bob Rock, whose methods challenged the band's previous recording habits. He encouraged the musicians to perform more as a unit and demanded numerous takes before selecting and editing the final performances.