VICÁLVARO, SPAIN—Government officials are planning to build thousands of housing units on the site of a necropolis that dates between the fifth and eighth centuries A.D., when the Germanic Visigoths ruled what is now Spain. The cemetery held the remains of 1,500 people, who must have lived in a nearby city whose location is unknown. Before construction begins, archaeologists will search the area for traces of the settlement, which they believe must be no farther than a mile from the necropolis. Opposition politicians have demanded the site be preserved, but the regional government has so far refused to grant it protected status.