What is the Partheon famous for?

Answer 1

The Pantheon was a temple dedicated to all gods (which is what the name means in Greek) by the Romans. It is well preserved because it was converted into a Christian church. It is a marvel of Roman architecture.

It is ruins (a rotunda) and its greatest marvel is its dome, which is still the largest unreinforced concrete dome in the world. At its top there is a round opening called oculus (eye). Apart from the entry door, it is the only source of light as there are no windows. It also serves for ventilation and cooling. The light from the oculus moves around the rotunda throughout the day, giving a reverse sundial effect. The floor is slightly convex towards its sides. It highest part is 30 centimetres (neatly 1 ft.) higher and lies 2 metres (2 ft.) to the north-east of the centre. It is concave at the centre and has 22 drainage holes.

The dome was built on top of a rotunda (round chamber) in concrete and was supported by a sophisticated system of relieving arches. Its downward thrust rests on eight vaults in the drum wall (which is 6.4 metres 21 ft. thick) which are supported by eight piers. The structure had a symmetrical order. . The height from the floor to the oculus is the same as the diameter of the inner circle of the rotunda, 43.3 metres (142 ft.). The height of both the wall of the rotunda and the dome are the same of the radius of the rotunda (half its dimension). Thus, the structure could contain a sphere 43.3 metre in diameter and could fit into a cube with 43.33x43.33 m sides. Despite its large size (43.43x2.67m) the dome weight is only 5 metric tons. This was achieved with a number of weight-saving strategies. Its thickness of 6.4 metres (21 ft.) at the base narrows to 1.2 metres (3.9 ft.) around the oculus. Successively less dense (and thus lighter) aggregates were used as the dome went upwards. To make concrete, the Romans mixed a volcanic rock called pozzolana with lime and added rubble aggregate to make it solid. Tuff and/or travertine stone was used for the lower layers, bricks for the middle ones and pumice and/or pottery shreds for the higher ones. If the same concrete had been used throughout, the downwards stress would have been 80% higher. Having the empty space of the oculus instead of an apex also reduced weight. This could be achieved only with Roman concrete. Modern concrete is fluid. Roman concrete was less fluid and had to be layered by hand. This allowed the use of different aggregates. Finally, the interior of the dome has five rings of 28 evenly spaced coffers (sunken panels). This is a decorative technique and this specific kind of layout is difficult to achieve. In the case of the dome, it also reduces weight because of the empty spaces in the squares. The arrangement of the coffers forms a honeycomb structure, which has a high strength-to-weight ratio. Thus, despite being hollow, it provides structural strength. The weight of the dome around the oculus (which is 9.1 metre, 30 ft., in diameter) is carried by as ring arches which form it.

The top of the rotunda which supports the dome has a series of relieving arches built into the brickwork which are visible outside. There are also relieving arches over the recesses (see below) on the inside. All these arches are hidden by the marble facing of the interior or by stone layering or stucco on the exterior. At the back of the temple there was a building to which the rotunda abutted, which helped to buttress the rotunda. There was no access to this building.

At the ground level of the Rotunda there are six wide recesses with two columns at their front. Their shapes alternate rectangles and semi-circles. There is an apse (a large semi-circular recess covered with a semi-dome) opposite the entrance. Between the recesses and at the ends of the circle of the rotunda there are seven niches. The recesses and the niches are famed by square pilasters (relief decorations on a wall with the appearance of a column). The columns and pilasters support a continuous beam. The apse is flanked by engaged columns (columns which partly project from the surface of the wall). Here the beam follows the base of its semi-dome. The walls of the rotunda have a facing of different colour marbles.

The upper level of the rotunda has windows which belong to a ring corridor which served to lighten the load of the structure. The windows are framed by pilasters made of porphyry. This wall also had a facing of different colour marbles (now lost).

Answer 2

The Partheon is famous for being one of the best-preserved ancient Greek temples in the world. It is also renowned for its architectural design, particularly its impressive dome which was a engineering feat during its time. Additionally, it is recognized as a symbol of classical antiquity and has influenced the design of many buildings throughout history.