 On December 21 , 1620 , the first landing party arrived at the site of what later became the settlement of Plymouth . Plans to immediately begin building houses , however , were delayed by inclement weather until December 23 . As the building progressed , twenty men always remained ashore for security purposes , while the rest of the work crews returned each night to the Mayflower . Women , children , and the infirm remained on board the Mayflower ; many had not left the ship for six months . The first structure was a " common house " of wattle and daub , and took two weeks to complete in the harsh New England winter . In the following weeks , the rest of the settlement slowly took shape . The living and working structures were built on the relatively flat top of Cole 's Hill , and a wooden platform was constructed atop nearby Fort Hill to support the cannon that would defend the settlement . 
