Apologies to simonuineill (cf) but Cafe Erra is a "straight Friendly" cafe as sometimes painted on the window! A source of great amusement to my straight brother.
I have been going there often during many visits to Prague over the past 5 years. It is only a couple of minutes walk from Old Town Square but, until the evening, it is always reasonably quiet. Free WiFi seems to be an attraction during the day. Dogs are very welcome and it is not unusual to find 3 or 4 enjoying themselves in there. Water is provided for them. The food has always been very good, especially for the price although the menu seems not to change very much - desserts are mainly cakes/gateaux which are bought in.
Evenings can be great fun with a good mix of gay and straight customers out to enjoy a drink before moving on to a club as it does close early (midnight at weekends) by Prague standards.
Unlike a lot of cafes etc in Prague, it is nice to see a nucleus of the same staff year after year who always give you a good welcome although very little English is spoken.
Don't be afraid of going on your own at busy times. People will always want to try out their English on you and give you a chance to try out your Czech.
If you travel to Prague with a partner and are not interested in the full on club scene then this would be an excellent place to visit for an enjoyable time with no late nights.
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