Deep within the Al Ain UNESCO World Heritage Site in Abu Dhabi (UAE), archaeologists have been discovering that our ancestors may have employed more sophisticated building techniques than we have previously given them credit for.
     The Al Ain Cultural Sites are mainly Bronze Age and Iron Age and this area formed the crossroads of ancient land routes across the Middle East. The Hili 2 site forms part of this complex, along with Hafit, Bidaa Bint Saud and Oases areas.
     The sophisticated technique simply involved the builder, or worker, leaving his fingerprint indentations in the formed mud bricks, before they had hardened and set. Not very advanced - you might think - but by doing this, when mortar was then applied between the bricks, as they were laid, the mortar would penetrate the fingerprint holes and form a much stronger and longer lasting bond.
     Other recent finds on the site, in the form of clay seals, show that this wet imprint technique was also used for either decoration or to establish ownership.

Edited from Fox News (3 June 2019)