Il Singer building, along Nevsky Prospect (the main street of St. Petersburg), opposite the Cathedral of Our Lady of Kazan, houses the homonymous Singer coffee.
Elegant and refined, an excellent combination of taste and culture, it is a bar / bookshop / library. The bar is well stocked with tea and hot chocolate and cakes of the most varied tastes. Customers, comfortably seated at their table, can read one of the many volumes available to them. Most in Russian language which of course you will never read, someone in English that you could perhaps browse, some tourist guides and postcards. But it doesn't matter, you might as well not touch any of the books that crowd the shelves, you would still enjoy the atmosphere, the smell and the magic that they donate to the venue.
And if you are lucky to find a free table in front of the windows, you can sip your tea while peering at the life that flows along the street or the architecture of the Kazan Cathedral, a St. Peter's Basilica in miniature with the colonnade and the dome and the large square as an entrance. The bar prices are quite high, by both St Petersburg and European standards, but it is absolutely worth it.
After all, what is a holiday if not letting go and living for a week free from constraints and restrictions? And if you visit a city, it's also nice to experience it and take in what special it has to offer. Stroll on the Nevsky prospect and not going into the Singer café is like going to Rome and not seeing the Pope. Unthinkable!