In Gilardi v. Hallam (1981) 30 Cal.3d 317, 320-321, the defendants' predecessors in interest made improvements to a portion of a parcel of property adjacent to their own, erroneously believing the improved portion belonged to them. The improvements were not considered part of the appraisal of the defendants' property. (Id. at p. 321.) Because the defendants and their predecessors did not pay taxes on the portion of the property in question, the defendants could not acquire title to the property by adverse possession, despite their open, notorious, continuous, and uninterrupted use of the property that was hostile to the owner and under claim of title. (Id. at pp. 321, 327.) However, the Supreme Court concluded the defendants might have been able to acquire a prescriptive easement over the property: "As pointed out above, failure to pay taxes bars the claim of title by adverse possession. However, because no taxes were separately assessed, the lack of tax payment would not bar a claim of prescriptive easement." (Id. at p. 327.) The Court California Supreme Court discussed the elements of (1) a claim of right and (2) use or possession hostile to the true owner. "The rule is settled in California that the requisite hostile possession and claim of right may be established when the occupancy or use occurred through mistake. In Woodward v. Faris (1895) 109 Cal. 12, 17, the court pointed out that most cases of adverse possession commenced in mistake and that the possession must be by mistake or deliberately wrong." (Gilardi, supra, 30 Cal.3d at p. 322.) The court in Gilardi also identified an exception to the mistake rule. Where land is occupied through mistake as to the property line with the intention to claim only to the true line, wherever it may be, a claim for adverse possession of the mistakenly occupied land will be denied. (Gilardi, supra, 30 Cal.3d at p. 322.) The court in Gilardi observed that it had discussed the mistake rule and its exception in Sorensen and "pointed out that the hostility requirement 'means, not that the parties must have a dispute as to the title during the period of possession, but that the claimant's possession must be adverse to the record owner, "unaccompanied by any recognition, express or inferable from the circumstances of the right in the latter." ' (Sorensen v. Costa (1948) 32 Cal.2d 453 at p. 459.)" (Gilardi, supra, 30 Cal.3d at pp. 322-323.) The Court found the evidence insufficient to satisfy the second--or "natural inference"--exception. There, a survey stake purporting to mark the property line between lot 1407, owned by the plaintiffs, and adjoining lot 1408, owned by the defendants, had been erroneously placed on a portion of lot 1407. (Id. at p. 320.) Relying on the position of the stake, the defendants' predecessors had improved a portion of lot 1407 with a sidewalk, sprinkler system, trees, and a lawn. (Ibid.) Lot 1408 was also improved with a house, while lot 1407 remained unimproved except for what the defendants' predecessors installed. (Id. at p. 321.) Finding that this evidence did not support the natural inference that taxes had been assessed on the improvements, the Supreme Court held the defendants failed to prove the requisite adverse possession element of the payment of taxes on lot 1407: "The parties and their predecessors were assessed taxes by lot number. There is no direct evidence that the sidewalk or ornamental plantings were considered in the assessment of the lots. There are no physical barriers, structures, or enclosures indicating that plaintiffs and their predecessors were excluded from using the sidewalk and planted areas on their land, or that the improvements were not a joint undertaking of the landowners. In the circumstances, the trial court was not required to infer that the assessor concluded the sidewalk and plantings reflected ownership of the disputed land by defendants and their predecessors." (Id. at p. 327.) The California Supreme Court stated that "ordinarily, when adjoining lots are assessed by lot number, the claimant to the disputed portion cannot establish adverse possession because he cannot establish payment of taxes. " However, there is an exception to this general rule when the claimant visibly possesses improvements on the disputed land. The Gilardi court explained that "where the claimant . . . has visibly shown occupation of a disputed strip of land adjoining the boundary, several cases have reasoned that the 'natural inference' is that the assessor did not base the assessment on the record boundary but valued the land and improvements visibly possessed by the parties. " (Id. at p. 327.) The Court concluded the defendants had not paid taxes on a portion of an adjoining parcel despite having made improvements to it. In Gilardi, the defendants owned lot 1408. (Id. at p. 320.) A survey stake purporting to mark the property line between lot 1408 and adjoining lot 1407, owned by the plaintiffs, had been erroneously placed on lot 1407. In reliance on the position of the stake, the defendants' predecessors had improved a portion of lot 1407 by installing a sidewalk, sprinkler system, trees, and a lawn. (Ibid.) Lot 1408 was improved with a house; lot 1407 was unimproved except for the improvements installed by the defendants' predecessors. (Id. at p. 321.) The Supreme Court agreed with the trial court the defendants could not prevail on an adverse possession claim because they had failed to prove payment of taxes on lot 1407: "The parties and their predecessors were assessed taxes by lot number. There is no direct evidence that the sidewalk or ornamental plantings were considered in the assessment of the lots. There are no physical barriers, structures, or enclosures indicating that plaintiffs and their predecessors were excluded from using the sidewalk and planted areas on their land, or that the improvements were not a joint undertaking of the landowners. In the circumstances, the trial court was not required to infer that the assessor concluded the sidewalk and plantings reflected ownership of the disputed land by defendants and their predecessors." (Id. at p. 327.)