WARSAW, Poland — A Jewish history museum in Warsaw has unveiled a reconstructed synagogue roof with an elaborately painted ceiling modeled on a 17th-century structure, presenting the first object that will go on permanent display in the highly awaited museum.

The wooden roof and ceiling will be a key attraction in the Museum of the History of Polish Jews, which is due to open next year in the heart of the city’s former Jewish quarter. Reporters in Warsaw were invited to view it Tuesday.

The museum will tell the story of Jewish life in Poland, a complex history spanning 1,000 years, but one that has been forgotten today by many people and which is often overshadowed by the Holocaust....