California Code, Revenue and Taxation Code - RTC § 23154

The tax imposed under this chapter is in lieu of all ad valorem taxes and assessments of every kind and nature upon the general corporate franchises of the corporations taxable under this chapter but is not in lieu of any taxes or assessments upon real property interests not otherwise exempted from taxation or assessment, that are created by special franchises owned, held, or used by those corporations. All those real property interests, not otherwise exempted from taxation or assessment that are created by those special franchises shall be assessed annually by the board, at their actual value, in the same manner as is provided for the assessment of other property to be assessed by that board under Section 19 of Article XIII of the California Constitution, and shall be subject to taxation to the same extent and in the same manner as other property assessed under that constitutional provision by the board.For purposes of assessing a real property interest pursuant to the preceding sentence, the value of intangible assets or rights shall not enhance or be reflected in the value of that real property interest, except that the real property interest may be assessed and valued by assuming the presence of intangible assets and rights necessary to put the real property interest to beneficial or productive use.