This is a unique opportunity to possess a Mid-Century Modern landmark designed by Master Architect Clare Henry Day, FAIA. The Marcum II house, often referred to as "the Treehouse on Sunset" is accessible by a pedestrian bridge from Sunset and secondary access at Valle Vista. Sitting under a canopy of jacaranda on over an acre of land, this legacy home optimizes one of the best views in Redlands. The open floor plan, features a living room with a two-sided corner fireplace, and floor-to-ceiling windows, leading to the outdoor terrace stretching across the entire north elevation. A separate open-plan dining room, two bedrooms, two bathrooms, a kitchen with an original Nu-tone food processor, custom cabinetry, and a unique pantry. Inside separate laundry room/craft room. The master bedroom focuses on the mountain view and has access to the full-elevation balcony. The bed wall is defined by historic wood paneling; a dressing room has new full-height closet systems that lead to the master bath. The bathroom that was recently remodeled features the original step-down Roman bath and floor-to-ceiling glazing, which creates a feeling of outdoor space. The second bedroom is equipped with a similar closet system and French doors that lead to a private balcony. The lower story is accessed by a spiral stair from the living room, and can also be accessed via outdoor stairs. The family room provides a large open space with glazing walls, a paver seating area, and a slider window. There is a separate approx., 400-square-foot room that isn't part of the home's square footage, but it includes a full bath and a large storage area. Steps lead downslope at the north to the avocado grove, horse corral, horse feeder, and garage. The property is of adequate size for a lot split or can incorporate extensive storage for "toys", or the addition of an ADU. Opportunity awaits!