Located in Budapest’s Terézváros district, Káldy Gyula utca is a street that typically falls outside my usual route when exploring the city. However, at number 6 on this street lies a hidden gem: a former Jewish prayer house. Constructed in 1867-1868 by János Lohr for Löwy Lindenbaum, the house was under the ownership of the Freundiger family from the late 19th century until its nationalization in the late 1940s. Mózes Freundiger, the son of the rabbi of Óbuda, purchased the house. According to Anna Perczel’s book “Unprotected Heritage,” the prayer house in the courtyard was used by the Jewish community until the 1930s. In Budapest, many synagogues are integrated into residential buildings, either within an apartment, on an entire floor like Hegedűs Gyula utca 3, or in the courtyard.