Sant Francesc de s'Estany

Torre de ses Portes watchtower at Ibiza's most southerly point

Torre de ses Portes was built in the late sixteenth century[3] as an early warning system for the inhabitants of the nearby village of Sant Josep from attack by pirates.[3] Of all the watchtowers on Ibiza this is the tallest of them. It is constructed from dressed stone which gives a smooth finish to the gently tapering walls.[3] To the top level there is a domed turret which covers the stairs. The tower has a narrow ground floor entry which behind has a dog-legged passage for further protection.[3] This passage leads into a spacious inner chamber with a strong vaulted roof. In one corner of this room there is a deep cistern which was designed to supply the occupants with ample water in the event of a prolonged siege. At the first floor level there is another doorway which was installed at a later date. Up on the roof of the tower, the outer walls were indented with a series of gun embrasures, although these have since been blocked off. The tower is mentioned in documents dating back to 1620[3] were the tower is described as being built to protect a long abandoned fishing settlement.

Torre des Carregador (The Loading Tower) or Torre de sa Sai Rossa (Red Salt Tower)

This watch tower is variously called by two names, Torre des Carregador, (the loading tower) or by the name Torre de sa Sal Rossa, (the red salt tower). This tower was designed by the Italian engineer Giovanni Calvi[3] to guard the salt working at Ses Salines on or around 1582. the tower stands at the far end of Platja d’ en Bossa.[3] The tower overlooked the landings used to load ships with the valuable salt.[3] The building is cone shaped, and has been described as an upside-down flower pot.[3] The tower stands 13 metres high and around its base the walls are 4 metres thick.[3] At the upper level the walls taper to a width of 2.6 metres thick and were designed to withstand cannon fire. Just below the towers' parapet there is a protruding stringer course of stone. The original entrance was at the base, and like the Torre de ses Portes has a dog-legged passage[3] for further protection, which was just wide enough for one man to pass through at a time.[3] To the end of this passageway there was an inner cross wall with a firing hole for a gunner to fire shots at point blank range if necessary. The tower was refurbished in 1763 (Inscribed above a window opening) when a more secure entrance was placed in the outer wall at the first floor level. The interior of this tower is divided into two stores with vaulted roofs the floors are linked by a spiral staircase which rises right to the roof. The ground floor is where the ammunition and all the provisions were stored. The smaller first floor was the guard room which had windows and a fireplace. On the roof would be small cannon with good range over the bay. Over the doorway at roof level was a bartizan (Matacàc) [3] which jutted out over the parapet. From here any defender could drop rocks through slots in the floor on to any attackers trying to gain access through the entrance below. Similarly, any attempt that attackers made to burn their way through the wooden door could be foiled by tipping buckets of sea water through the slots.[3]

At the south eastern end of the island is the Illa des Penjats lighthouse. The building is of a rectangular shape with the light tower rising from the structure. There are also two wings, which were added on the side after the lighting apparatus was changed. The building is constructed of stone blocks and is whitewashed. The lighthouse was built to guide shipping through the narrow strait of Es Freus which lies between Ibiza and Formentera.