Spanish colonial architecture is a building style rooted in early Spanish settlements, with its residential form refined in Southern California during the 1920s and 1930s. It’s defined by stucco exteriors, arched openings, exposed wood beams, and handcrafted detail throughout. Kingdom & Co.’s Castella Estate in Centennial Hills is a ground-up custom home built in this authentic style. Castella Estate — Spanish colonial custom home in Las Vegas.