Don't let the name put you off – it literally means Mother's Mouth Coffee – this little cafe is always heaving with locals. It's halfway along the bike path between the ferry pier and Guandu Bridge. With benches on the bank and moist brownie slices, it's a justifiably popular spot to take a break, especially now they have a coffee-infused ale.
There's another branch of Mommouth next to Hobe Fort in Tamsui.