Before Roland Park existed, Baltimore constructed a reservoir called Lake Roland, which served the city until 1915. Soon after, Robert E. Lee Park opened. It encompasses 450 acres of woodland and wetland around Lake Roland and became a favorite spot for hikers, picnickers, canoeists and kayakers. The park, free and open to the public, permits dogs on leashes, but dog owners prefer Paw Point Dog Park to allow their dogs to run free. Paw Point requires a membership.
Also free, and open year round, Cylburn
Arboretum began life as the summer mansion and grounds of Jesse Tyson, a wealthy businessman. Today the mansion still stands, and the 207 acres support many species of trees and wildflowers based on Tyson's original plantings, gardens, greenhouses and exhibits of watercolor paintings of Maryland wildflowers. The estate's former carriage house contains a nature museum as well. The Arboretum permits leashed dogs on the grounds, but not in the buildings. Every Halloween, Cylburn plays host to "ArBOOretum", a celebration featuring carriage rides, pumpkin carving and a costume contest.