The summary judgment entered below is affirmed on the principle that a landowner is under no duty to keep an abutting sidewalk free of accumulated leaves, sap, algae or any other natural obstruction. Strong v. Richfield Agency, Inc., 460 N.W.2d 106 (Minn.App. 1990); Restatement (Second) of Torts § 349 (1965); see Sullivan v. Silver Palm Properties, Inc., 558 So.2d 409 (Fla. 1990); Gallo v. Heller, 512 So.2d 215 (Fla. 3d DCA 1987); Richmond v. General Engineering Enters., 454 So.2d 16 (Fla. 3d DCA 1984); Ponte v. DaSilva, 388 Mass. 1008, 446 N.E.2d 77 (1983).