An 800-year-old, pre-Columbian burial ground with baskets full of human remains was unearthed at a building site outside San Jose, National Museum archaeologists said Tuesday.

The burial ground, dating from about the year 1200, yielded 26 sets of human bones from children to adults, contained in baskets made of plant fiber, an unusual material for native groups predating the discovery of the New World by Christopher Columbus.

Gutierrez said the burial site was first discovered two months ago by workers digging foundations for a new house, but was kept from the public while archaeologists completed their excavations. It lies in an empty lot surrounded by residential homes....