Temple or Observatory
In Zoroastrian books it is quoted that the holy Zoroaster was worshipping in Kaaba and this word later were adopted by the Arabs as a place of worshipping the God. In the age of Cyrus the Great, Persians used to call the land where is known as Amman, the capital city of Jordan, Mecca and this is a Persian word as well which is used to call current place of Mecca and the Kaaba is holy building for Muslims.
There is a building with a different architecture in Naghsh-e Rostam in Shiraz which is mistakenly called Kabaa of Zoroaster (the place where he used to worship), this name firstly used by the Arabs when they invade Iran in the age of Sassanids dynasty. Because they didn’t know about it and its use, they assumed this building as a place for idols but Persians never worshiped the idols and and they were monotheist in the other hand because Zoroastrians called temples “Kabaa”, they called this building Kaaba as well, so this building stayed as a temple for many years.
Recently, Reza Moradi Ghias Abadi, a researcher who had great efforts on studying old Persian, found out the use of this building and he published his discovery in his book in Persian. Before his discovery, the building was considered as a treasury, a governmental documents storage, a place to archive documents, temple or a place for Avesta (The holy book of Zoroaster) but Ghias Abadi proved that this unique building is actually the most accurate building to calculate solar calendar in compare to all other buildings constructed for this reason in the world. There are many building like this across Iran and they are built only for this reason. All of them are only able to calculate some specific days of the year for example the first days of seasons and even they are not compliant with Solar calendar but this sophisticated observatory building can calculate many days and months of the year accurately and Zoroastrians were used them to determine their specific events in the year, particularly the Nowruz (The New Day) which is the first day of the year in solar calendar and it is the first day of spring and is very important day for Iranians.
To build such observatory place the constructors should knew many scientific issues on geography and astronomy and these observatories places prove that 3000 years ago Achamenians were aware of many facts about the earth and solar system that many years later were revealed by scientists.
In Zoroastrian books it is cited that Zoroaster were calculating the Nowruz in this observatory building. Nowruz is starting from a place where the first rays of the sunlight are shed to and according to his calendar Nowruz starts every 700 years from Iran. The last time was 300 years ago. In 2008 Nowruz were commenced from Paris and Brussels and this year it was from Toronto in 2009.
Next year (in 2010) it will start from a location between Alaska and Hawaii
Many of such buildings were destroyed as they are supposed to be fire temples [Atashkade] but some of them like those in Tafresh and Niasar were survived until now. Unfortunately this observatory building in Shiraz in Naghsh-e Rostam is near the Sivand water barrier and placed in danger of destroying. Sadly it is not registered as a national heritage in united nation. And of course it could be proposed as one of the seven wonders in the world.