H. Alexander Walker Residence, Neoclassical residence in Nuuanu Valley, Hawaii, US

The H. Alexander Walker Residence is a Neoclassical dwelling in Nuuanu Valley distinguished by grand columns and balanced proportions. The property includes formal Japanese gardens planted with ferns, stones, and fruit trees.

The estate was built in 1903 by George Rodiek and later became home to H. Alexander Walker, president of American Factors. Walker held connections to King Kalakaua's cabinet, adding to the property's historical standing.

The estate goes by the name Mamalu, which means Shady Lawns, blending Neoclassical architecture with Hawaiian residential traditions and Japanese garden design. This combination shapes how the space looks and feels when walking through it.

The estate sits in the upper Nuʻuanu Valley of Honolulu, on 5.86 acres of grounds. It is a private property still maintained in its original condition, so visits are not open to the public; the house can be seen from the road. The site was added to the National Register as site 73000665.

Fleet Admiral Chester W. Nimitz dined with the Walkers and played horseshoes on the grounds during World War II. Their cook, a Japanese national named Hara, prepared hundreds of meals for the Pacific Fleet high command and was congratulated by Nimitz for them.