Complex sentence: In 2010, a 3.5-kilometre long educational trail called "Trees of the World" was opened in the arboretum, which enables visitors to see and obtain botanical information on 25 major species of trees found in North America, Asia and Europe.
Split into simpler sentences: In 2010, a 3.5-kilometre long educational trail called "Trees of the World" was opened in the arboretum. It enables visitors to see and obtain botanical information on 25 major species of trees found in North America, Asia and Europe.