Ziggurats.
The mesopotamia region was famous for Ziggurats. Some of the most famous Ziggurats of this region are known as The Great Ziggurat of Ur and Khorasabad. These structures looked like gigantic pyramids and had the form of hundreds of steps. They were not considered places of worship. Instead they were merely believed to house gods. That is the reason why sacrifices were made here and offerings to appease the god were made here too. This was a tradition that went on during the 3rd millennium BC.
B. the freedom to assemble together for peaceful meetings
this freedom is protected by the first amendment to the constitution, which reads "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances."
They allowed for travel against a rivers current Hope this helps! ;D