The Republic of Panama grants to the United States in perpetuity the use, occupation and control of a zone of land and land under water for the construction, maintenance, operation, sanitation and protection of said canal of the width of ten miles extending to the distance of five miles on each side of the centre line of the route of the canal to be constructed; the said zone beginning in the Caribbean Sea three marine miles from mean low water mark, and extending to and across the isthmus of Panama into the Pacific Ocean to a distance of three marine miles from mean low water mark, with the proviso that the cities of Panama and Colon and the harbours adjacent to said cities, which are included within the boundaries of the zone above described, shall not be included within this grant. The Republic of Panama further grants to the United States in perpetuity the use, occupation and control of any other lands and waters outside of the zone above described which may be necessary and convenient for the construction, maintenance, operation, sanitation and protection of the said canal or of any auxiliary canal or other works necessary and convenient for the construction, maintenance, operation, sanitation and protection of the said enterprise. The Republic of Panama further grants in like manner to the United States in perpetuity all islands within the limits of the zone above described and in addition thereto the group of small islands in the Bay of Panama, named Perico, Naos, Culebra, and Flamenco. Article 3. The Republic of Panama grants to the United States all the rights, power and authority within the zone mentioned and described in Article 2 of this agreement and within the limits of all auxiliary lands and waters mentioned and described in said Article 2 which the United States would possess and exercise if it were the sovereign of the territory within which said lands and waters are located to the entire exclusion of the exercise by the Republic of Panama of any such sovereign rights, power or authority. Article 4. As rights subsidiary to the above grants the Republic of Panama grants in perpetuity to the United States the right to use the rivers, streams, lakes and other bodies of water within its limits for navigation, the supply of water or water-power or other purposes, so far as the use of said rivers, streams, lakes and bodies of water and the waters thereof may be necessary and convenient for the construction, maintenance, operation, sanitation and protection of the said canal. Article 5. The Republic of Panama grants to the United States in perpetuity a monopoly for the construction, maintenance and operation of any system of communication by means of canal or railroad across its territory between the Caribbean Sea and the Pacific Ocean. Article 6.