Babylonia (7th Singularity): Abandoned City Babylon (Free Quest) is the best AP-saving & time-saving location to farm Yggdrasil Seed. You'll get around 5x Yggdrasil Seed by spending 200 AP.
Orleans (1st Singularity): Jula (Free Quest) is the first location you unlock to farm Yggdrasil Seed.
Note: No Bond CE's here.
5 Star Servants Tier List
Best Servants [★4]
Christmas event [JP 2016 Rerun]
FGO Reroll Tier List
Holy Night Supper
Piece of Year 2030