Unfortunately, the one thing that I always remember about this place is that they forgot my…read moremarshmallows. I paid extra for marshmallows, and when my hot chocolate came it was without the little mountain of tiny marshmallows I was expecting. I was still fairly new to Cardiff at the time, and a little shy, so I sat quietly and hoped that perhaps they had sunk to the bottom and I'd find them as I started drinking. Sadly, however, no marshmallows were to be found, and then it was too late to do anything about it.
This aside, Waterloo Gardens Teahouse is a lovely little shop, in the quiet area of Penylan with a nice selection of drinks and cakes, and comfy sofas. The coffee is fair-trade, there is a wide variety of tea, and they change the art on the walls regularly, exhibiting a different artist each month, which is a nice touch.
Just make sure they give you the marshmallows you're paying for.