In the middle has come to represent

In ancient Mesopotamia ziggurats were built as part
of a temple, they are a massive step tower up to a temple on the top, however no
one knows the true purpose of these. Stupas are a monumental building from India
Buddhism built to house sacred relics or remains of Buddha himself. A ziggurat
is made of sun-baked bricks on the inside and fire-glazed bricks facing outward,
and is built as a square platform that has two to seven tiers. As the ziggurat
becomes taller the tiers become stepped further in until the top where it flattens
off and that is where a temple would stand. In order to get to the temple there
would be either a large external staircase, such as in Ur, or a spiralling
staircase. Due to the ziggurats being constructed of sun-baked mud bricks, they
deteriorated with age and were regularly rebuilt by Kings of the time. A stupa,
made out of timber and stone, has many different elements, around the stupa is
a railing (Vedika) with gateways in the middle (Toranas) and once through the
gates you are at the stairways (Sopanas) and the iconic dome (anda) of the
stupa with its crown (parasal) on top. Each of these elements represents something;
the anda represents a mound of dirt covering the Buddha’s remains, the harmika
(the square railing around the parasal) marks the stupa as a sacred burial
site, the parasal is to protect it from the elements and the pillar in the
middle has come to represent the pivot of the universe. Each of these elements
also represents part of the path to enlightenment, a Buddhist belief. With
stupas being made from stone and timber they are sturdier and have stood the
test of time whereas ziggurats are very weathered and not many, of the few
there are, remain in good condition. While being very different buildings, both
a ziggurat and a stupa have something in common which is there is no internal
space in either of the structures and that not many people can use them. Not
many people can use a ziggurat as it is only the high priests that could use
the structure. Although stupas can be visited by many no one can actually use
the structure as there is no way to enter.