Key points of Map of Arroyos - Assassin Contracts - Assassin's Creed IV: Black Flag
15. Tomb Raiders
Your target is as far as the Pinos Isle so sail, or fast-travel there, if you have already visited this island. After you get there, follow the skull symbol. Your target is at the topmost-but-one level of the pyramid, standing atop the stairs. It is best to eliminate the guards, at one side of the pyramid first, climb up and eliminate the target from above.
16. A Last Drink for the Road
No reward for staying out of combat. The target is in a small restricted area, close to the coop. Over the rooftops, make it over to the target and attack him from above. If you fail, the target will escape to the frigate in the harbor and sail out into the sea. In such a case, you will have to catch up with the vessel, damage it and kill the target during boarding.