Bulgaria bought the house in Vienna's third district in 1975 and has run its cultural institute there ever since — a building planned from 1925 by Ludwig Wittgenstein with the architect Paul Engelmann for Wittgenstein's sister Margarethe Stonborough, and occupied at the end of 1928. The institute is the cultural arm of the Bulgarian embassy: exhibitions, readings, lectures and concerts, among them a programme by the Youth Orchestra Plovdiv in November 1993.