Pool

The outdoor pool or "natatio" has a rectangular plan, of which only 9.7 meters have been preserved. One of its short sides is finished in the shape of a lobed apse, however, the other has not been preserved.

The entire perimeter of the pool is surrounded by three steps or steps, in which remains of hydraulic plaster can be seen in certain areas. A small part of the steps has been kept as it was located, leaving the soul of the stands visible. The bottom of the "natatio" was covered with rectangular marble plates, of which ten are preserved "in situ", and traces of the location of the rest of the missing slabs. The color difference between them marks a linear design in the background, combining orange-brown and blue-gray.

Plate dimensions
Plate 1: Blue-gray, maximum length: 85 cm and maximum width: 51 cm
Plate 2:Blue-gray, maximum length: 97 cm and maximum width: 51 cm
Plate 3:Blue-gray, maximum length: 126 cm and maximum width: 50 cm
Plate 4: Orange brown, maximum length: 87 cm and maximum width: 33 cm
Plate 5: Orange brown, maximum length: 110 cm and maximum width: 69 cm
Plate 6: Orange brown, maximum length: 97 cm and maximum width: 76 cm
Plate 7:Blue-gray, Maximum length: 96 cm and maximum width: 59 cm
Plate 8: Orange brown, Maximum length: 98 cm and maximum width: 64 cm
Plate 9:Blue-gray, Maximum length: 30 cm and maximum width: 22 cm
Plate 10: Blue-gray; Maximum length: 26 cm and maximum width: 39 cm

The steps, made up of three steps, are built with boulders, stone elements and tegulas joined with mortar and covered with hydraulic mortar. Its exterior appearance was embellished with green marbles on the partition or riser of the step, of which only the start of the plates is preserved, especially in the lower tier. The soul of the stand is reinforced with tegulas and lined with white marble on the tread or upper part of the steps.

Dimensions of the stands
Step 1: Maximum footprint: 37 cm and maximum height: 37 cm
Step 2: Maximum footprint: 37 cm and maximum height: 40 cm
Step 3: Maximum footprint: 57 cm and maximum height: 39 cm

The Romans bathed a lot, the documentation tells us that they washed every day and for this they not only had adequate areas in their own houses but also built public baths, originally called balneas. Later, those sponsored for the people, whether by rich men or emperors, were called "thermas." This term became widespread after Emperor Agrippa around 25 AD. c.

Among the main components of a hot spring, it was not unusual to find a pool called a natatio. It is characterized by being large, with cold water and open to the outside, since they were used to bathing in rivers and washing with water at room temperature. It was located close to the arena, that is, to the porticoed place where they did sports and ball exercises, so they could cool off their sweat. Unlike the Greeks who opted more for physical exercise, the Romans preferred baths which had also become a meeting place, social gathering and center of worldly life.

According to Martial (2nd half of the 1st century) the thermal itinerary passed first through the palestra and the "natatio", that is, in both cases, open-air areas. This cold space was preceded by a changing room and a shallow pond for washing feet. Once the body had been exercised, the baths themselves could be accessed through the "apodyterium" or vestibule, which was generally located in front of the previous rooms.

In "Caesaraugusta", for now, only this outdoor pool and part of the porticoed area have been found. It was built by partly destroying previous republican baths, especially the latrine area. Chronologically it was used from the middle of the 1st century AD. lasting in operation until the end of the 3rd century AD.

These thermal complexes were open to the public from noon to sunset, that is, at the times when the sun could heat up the most. To simplify access to the water of the "natatio" three steps were built around the perimeter. The entire space was half covered by a portico of columns, of which eight plinths are preserved, so the heat of the sun only affected the Romans who were in the pool.

To facilitate the necessary waterproofing, in addition to using lime mortar with abundant clay fragments and a high percentage of ash in their manufacture, these elements were covered with marble slabs. In "Caesaraugusta" these slabs draw two darker parallel lines, as a frame inside the pool, through the color difference of the marbles. This material was also used to create a barrier against splashing water in the porticoed area. It is a marble strip, like a plinth, that occupied the intercolumnia of the porch, thus forming a perimeter around the natatio, whose main function was to prevent its water from reaching the interior of the portico.

The dimensions of both the pool and the porch would be larger than the current ones. The natatio possibly reached 16 meters in length, maintaining a depth of one meter to allow swimming in it. These spaces were usually covered with marble slabs decorated with geometric figures, shields and other motifs. The ornamentation of the room would be complemented with several sculptures and a small nymphaeum in the southern area.