Children and parents scaled the storm fencing around the mounds in Washington Sq. Park two weekends ago to protest the Parks Department’s failure to include the dilapidated, enigmatic play hills in the park’s renovation, to start at summer’s end. Packing chalk, they wrote, “Save The Mounds, We Love Them,” on one of the three, 6-foot-tall nubs, and rolled balls and toy cars up and down the hills’ sides. A Park Enforcement Patrol officer appeared and told the group they would be arrested if they didn’t move off the mounds; the parents said they were prepared to get arrested, and held their ground — and their mounds — defiantly for some time until finally being persuaded to leave. The area with the mounds — the last remnants of an adventure playground from the park’s last renovation in 1969 — is not included in phase one of the park’s two-year refurbishment plan. The parents say two years ago, Parks promised they would repair, resurface and reopen the mounds — Downtown’s only hills and a favorite toddler winter sledding spot — but now plan to bulldoze them. Parks plans a new adventure-type playground for adolescents at the site.