Hollywood's Roosevelt Hotel, which hosted the first Academy Award ceremony in 1929. The building is located along Hollywood Boulevard, directly southwest of today's H&H CENTER.
Photo from Wikipedia / Gary Minnaert

Hollywood's Pantages ["Pan-tay-jus"] Theatre, which was an Oscar Night venue for the years between 1950 and 1959. It is located at the Hollywood & Vine intersection, several blocks east of the H&H CENTER.
Photo from Wikipedia / "Captain-tucker" / LA Times