The design feature of Hagia Sophia that is considered the most daring is the main dome encircled by a band of forty windows.
Explanation
Hagia Sophia is consideed by many as the masterpeice of Bryzantine architecture and it is located in Turkey. The daring feature of the masterpeice is doubtlessly the central dome which is 184 feet high and has a diameter 102 feet. The very fact that the huge dome sits on pendentives and not on a flat solid base makes the structure a daring one.
Pendentives are supporting arches at square corners makes a circular plan possible. The main dome can be called a succession of smaller domes because the arches at east and west are extended by half domes that rest on even smaller portecos.
Answer: I think the answer is Riverbed. Let me know if I'm right or not.
Ussr, China, North Korea, South Vietnam, Cuba
Slave ships were large cargo ships specially converted for the purpose of transporting slaves. ... As many as 20 million Africans were transported by ship. The transportation of slaves from Africa to America was known as the Middle Passage.