A popular place located on the embankment in Gorky Park. There you can get a cup of tea - very good to keep warm in winter (and they have so many varieties!). When it's hot, go for a scoop of ice-cream (which is also made with tea)
Perfect location (easy to find when you walk in Gorky Park and decide to stop for a while). The variety of ice-creams, tea and tea cocktails is really non-trivial and worth trying! There are many SAMOVARS in the cafe, one of them is used for boiling water
In winter, they also serve tea on the ice ring