(1) "Premises" means any real estate and all improvements erected thereon.

(2) "Separate building" means each unit of a building consisting of two or more units separately secured or occupied.

(3) A person "enters unlawfully" or "remains unlawfully" in or upon premises when the person is not licensed, invited, or otherwise privileged to do so. A person who, regardless of his or her intent, enters or remains in or upon premises that are at the time open to the public does so with license and privilege unless the person defies a lawful order not to enter or remain, personally communicated to him or her by the owner of the premises or some other authorized person. A license or privilege to enter or remain in a building that is only partly open to the public is not a license or privilege to enter or remain in that part of the building that is not open to the public. Except as is otherwise provided in section 33-6-116 (1), C.R.S., a person who enters or remains upon unimproved and apparently unused land that is neither fenced nor otherwise enclosed in a manner designed to exclude intruders does so with license and privilege unless notice against trespass is personally communicated to the person by the owner of the land or some other authorized person or unless notice forbidding entry is given by posting with signs at intervals of not more than four hundred forty yards or, if there is a readily identifiable entrance to the land, by posting with signs at such entrance to the private land or the forbidden part of the land. In the case of a designated access road not otherwise posted, said notice shall be posted at the entrance to private land and shall be substantially as follows: