Synonyms for Encampment (same or very similar meaning)
WordNet sense 1 (a site where people on holiday can pitch a tent):
bivouac, campground, campsite, camping area, camping ground, camping siteWordNet sense 2 (temporary living quarters specially built by the army for soldiers):
camp, cantonmentWordNet sense 3 (the act of encamping and living in tents in a camp):
camping, bivouacking, tentingFrom the ODE community, based on WordNetadd/edit