Study the writing on the gravestones and try to piece together the area's history at Lidazhao Martyrs Cemetery. You'll find lots of interesting stories among the monuments here.
You'll soon discover why this Haidian burial ground is visited by many travelers. If you're looking for other things to keep you busy, Tsinghua University, Summer Palace, and Old Summer Palace are in the area too. They won't take you long to get to from Lidazhao Martyrs' Cemetery.