how is it connected to asia?
It was also used extensively in Mughal architecture, India and even in places in the Middle East and Central Asia
Onion dome
it was also used extensively in Mughal architecture, 
what is referred as onion dome? Is referred to a dome whose shape resembles an onion and is usually associated with Russian architectural style. where is it located? Russia what symbol does it represent? It is believed to symbolise burning candles
wiki:20243275
Onion dome [SEP] Asia
The onion dome is not only found in Russian architecture: it was also used extensively in Mughal architecture, which later went on to influence Indo-Saracenic architecture. Outside India, it is also used in Iran and other places in the Middle East and Central Asia. At the end of the 19th century, the Dutch built Baiturrahman Grand Mosque in Aceh, Indonesia, which incorporated onion shaped dome. The shape of the dome has been used in numerous mosques in Indonesia since then.