elephant barn, now converted into a picnic shelter and decorated with tile mosaic of various animals and a life-size brick relief sculpture of an elephant and calf. The zoo moved again in 1959 to its present location at the park's southern edge. In 1958, the Oregon Museum of Science and Industry (OMSI) moved into a new building in the southwest corner of Washington Park, adjacent to the new zoo. In 1971, the Western Forestry Center (now the World Forestry Center) opened a forestry museum north of OMSI. OMSI moved out of the park to a new location in 1992, and the Portland Children's Museum took over OMSI's former building in 2001. The Children's Museum closed in 2021. On March 15, 2018, the Portland City Council adopted a master plan to guide development of Washington Park over the next 20 years. The plan called for improved transportation and accessibility within the park, as well as improvements to park features such as the arboretum. The City of Portland is in the process of replacing the two outdoor reservoirs with underground reservoirs covered by reflecting pools, due to their age and a federal mandate to cover all reservoirs. The project is expected to be completed by the end of 2023. The $67 million project attracted opposition from historical preservationists and residents concerned about construction impacts. Notable features Washington Park has over of trails, some of which are part of the 40-Mile Loop connecting Washington Park with Pittock Mansion and Forest Park to the north and Council Crest to the south. The Wildwood Trail through Forest Park begins in Washington Park near the Oregon Vietnam Veterans Memorial. In 2019, the City of Portland constructed Barbara Walker Crossing at the northern edge of Washington Park to allow Wildwood Trail users to safely pass over West Burnside Street. The International Rose Test Garden is the oldest official, continuously operated, public rose test garden in the United States. Dedicated in 1924, it displays more than 10,000 rose plants of more than 650 varieties. It includes a Shakespeare garden within its boundaries, and borders an alpine garden at its southern end and a secluded oval-shaped "secret garden" to the north. The Washington Park Amphitheater is located in the Rose Garden and hosts many public concerts, including the Washington Park Summer Festival, an annual free concert series normally presented in August. The Hoyt Arboretum contains nearly 6,000 individual trees