If you find yourself in Budapest’s Castle District, keep an eye out for a discreet brass sign next to the grand green doorway of a somewhat dilapidated building.  

Walking through the door, a guard might be there to give you directions. If not, continue straight through the building into a courtyard, then turn left and go straight through the next building into another courtyard. Turn right, and continue until you see a collection of telephone paraphernalia presumably too big to fit in the museum. Ring the bell.

The museum is organized around the history of the telephone in Budapest, from the days when there were few enough people in the phonebook that operators were expected to memorize all their names and numbers, right up until the 1980s and the beginnings of mobile technology.

Apart from seeing the inner workings of phones, there are plenty of strange nuggets of historical information, beautiful photographs, and even a collection of ornate phones owned by past Hungarian leaders (some more popular than others, as the guide will tell you). 

The final room is devoted to a complete working Rotary 7A1-type sub-exchange, the only of its kind in the world that still functions. You can even make a call after the great beast is fired up!  The guide, who spent his career as a telephone engineer in Budapest, has an infectious enthusiasm. He does not speak fluent English but has enough to get his point across, answer your questions and be thoroughly charming.  It is a small museum but you could easily spend an hour wandering through.