Cal. Rev. & Tax. Code § 231

(a) Property that is owned by a nonprofit corporation and leased to, and used exclusively by, government for its interest and benefit shall be exempt from taxation within the meaning of “charitable purposes” in subdivision (b) of Section 4 and Section 5 of Article XIII of the California Constitution if:
1. (1) All of the provisions of Section 214 are complied with, except paragraph (6) of subdivision (a). For purposes of paragraph (6) of subdivision (a) of Section 214, irrevocable dedication to charitable purpose shall be deemed to exist if the lease provides that the property shall be transferred in fee to the entity of government leasing the same upon the sooner of either the liquidation, dissolution, or abandonment of the owner or at the time the last rental payment is made under the provisions of the lease.
2. (2) All of the provisions of Section 254.5 relating to owners are complied with, commencing during calendar year 1969.
3. (3) All of the provisions of Section 214.01 are complied with by March 15, 1970.
(b) As used in this section “property” means:
1. (1) Any building or structure of a kind or nature which is uniquely of a governmental character and includes, but is not limited to, the following:
  1. (A) City halls.
  2. (B) Courthouses.
  3. (C) Administration buildings.
  4. (D) Police stations, jails, or detention facilities.
  5. (E) Fire stations.
  6. (F) Parks, playgrounds, or golf courses.
  7. (G) Hospitals.
  8. (H) Water systems and waste water facilities.
  9. (I) Toll bridges.
2. (2) Any other property required for the use and occupation of the buildings and leased to government.
3. (3) Any possessory interest of the nonprofit corporation in property and in the land upon which the property was constructed and so much of the surrounding land that is required for the use and occupation of the property.
4. (4) Any building and its equipment in the course of construction on or after the first Monday of March, 1954, together with the land on which it is located as may be required for the use and occupation of the building when the building and equipment is being constructed for the sole purpose of being leased to government to lessen its burden.
  “Uniquely of a governmental character” means the property, except hospitals, water systems, waste water facilities, golf courses, and toll bridges, is not intended to produce income or revenue in the form of rents or admission, user or service fees, or charges.
(c) As used in this section “property” does not include any possessory interest of any person or organization not exempt from taxation.
(d) As used in this section “nonprofit corporation” means a community chest, fund, foundation or corporation, not conducted for profit, and no part of the net earnings of which inures to the benefit of any private shareholder or individual and that nonprofit corporation is organized and operated for the sole purpose of leasing property to government and to lessen the burden of government and, in fact, only leases property to government. That nonprofit corporation shall qualify as an exempt organization either under Section 23701f or 23701u of this code or Section 501(c)(4) of the Internal Revenue Code of 1986. This subdivision is not intended to enlarge the “welfare exemption” to apply to organizations qualified under Section 501(c)(4) of the Internal Revenue Code of 1986 but not otherwise qualified for the “welfare exemption” under this section. Nonprofit corporations that meet the tests of this subdivision are deemed to be organized and operated for charitable purposes.
(e) As used in this section “government” means the State of California, a city, city and county, county, public corporation, and a hospital district.
(f) The exemption provided for in this section shall be deemed to be within the “welfare exemption” for purposes of Section 251.
(g) For leases first entered into by and between government and a nonprofit corporation on or after January 1, 1969, all requirements of this section shall be met for the property and the nonprofit corporation to qualify for the exemption provided by this section.
(h) For leases first entered into by and between government and a nonprofit corporation on or before December 31, 1968, all requirements of this section shall be met except that the last unnumbered paragraph of subdivision (b) shall not apply and for the purposes of subdivision (b)(1) the list of real property qualifying for this exemption includes community recreation buildings or facilities, golf courses, airports, water, sewer and drainage facilities, music centers and their related facilities, and public parking incidental to and in connection with one of the buildings or structures set forth in this section.
(i) Property exempt under this section shall be located within the boundaries of the entity of government leasing the same.
(j) Where the construction has commenced on or after January 1, 1969, improvements shall be advertised and put to competitive bid to qualify for the exemption provided by this section.
(k) For purposes of subdivision (d), a nonprofit corporation shall not be deemed to be qualified as an exempt organization unless the organization files with the assessor a valid organizational clearance certificate issued pursuant to Section 254.6.