Complex sentence: On 20 April, his 56th birthday, Hitler made his last trip to the surface and in the ruined garden of the Reich Chancellery awarded Iron Crosses to boy soldiers of the Hitler Youth.
Split into simpler sentences: On 20 April, his 56th birthday, Hitler made his last trip to the surface. In the ruined garden of the Reich Chancellery, he awarded Iron Crosses to boy soldiers of the Hitler Youth.