P.R. Laws tit. 31, § 1043
The following are immovables:
(1) Lands, buildings, roads and structures of every kind adherent to the soil.
(2) Trees, plants and ungathered fruits, while they are not separated from the land or form an integral part of an immovable.
(3) Everything attached to an immovable in a fixed manner, in such a way that it cannot be separated from it without breaking the matter, or causing injury to the object.
(4) Statues, reliefs, paintings, or other objects of use or ornament, placed in buildings or on lands or tenements by the owner thereof in such a manner that they become attached permanently to the property.
(5) Machinery, vessels, instruments or implements intended by the owner of the tenement for the industry or works that he may carry on in any building or upon any land and which tend directly to meet the needs of the said industry or works.
(6) Animal houses, pigeon houses, bee hives, fish ponds or breeding places of a similar nature, when the owner has placed or preserves them with the intention of keeping them attached to the tenement and forming a permanent part thereof.
(7) Manures or fertilizers intended for the cultivation of the land, when upon the place where they are to be employed.
(8) Mines, quarries and slag lands, while the matter thereof forms part of the beds, and waters, either running or stagnant.
(9) Docks and structures which, though floating, are intended by their nature and the object for which they are designed, to remain at a fixed place in any river or lake, or on any shore.
(10) Administrative concessions for public works, and servitudes and other real rights, attached to immovables.
History —Civil Code, 1930, § 263.