The Guidelines and Help Center contain a lot of information about general cache placement and what you need to know. The information in this Wiki is based on these guidelines as applied to the British Overseas Territory of Gibraltar.
Gibraltar Nature Reserve (formerly the Upper Rock Nature Reserve)
This large nature reserve is a protected area managed by the Gibraltar Ornithological & Natural History Society. The reserve has two sections, one (the larger) in the north and a smaller one in the south. Due to the sensitive nature of the flora and fauna in the reserve and the fact there are many archaeological features caches may only be placed with permission.
You may view the extent of the reserves in the Gibraltar Geo Portal Map (see screen shot below). When the map opens, tick the box on the left, Nature Reserve Area.
You can also download a KML file of the reserve from here - scroll down and find the file gibgis:nature_reserve_area_25830 then click the link KML on the right. KML files will open in Google Earth which is a free download for a PC and also as apps for Apple and Android.
The local laws and guidelines for geocaching placement vary from place to place. As community reviewers learn geocache placement policies for a certain location, they can add it here. This site may not be a complete or accurate list of land policies. These policies are made by the land owner or manager, they are neither the reviewer’s nor Geocaching HQ’s. This guide is just for reference, if no policies for the area you’re looking for are listed, that doesn't mean no policies exist. You must still obtain permission to place your geocache from the landowner or land manager,comply with all applicable laws, and follow the Geocaching Listing Requirements.
If you have an update, email the community reviewer(s) listed.