The approval by the National Parks Board (Commissioner of Parks and Recreation) in 2016 for a site investigation in the Central Catchment Nature Reserve for feasibility studies for a Mass Rapid Transit tunnel under the surface of the reserve, and the subsequent decision by the Government in 2019 to go ahead with the tunnel, have raised two important legal questions: what is the scope of activities that may be permitted in a nature reserve; and what is the depth to which nature reserves are protected under the Parks and Trees Act? These are important questions because future subterranean developments in the nature reserves cannot be ruled out, and such developments must be guided by a clear understanding of what is and is not permitted under the Act. This note hopes to contribute to a discussion of the legal questions through an examination of the relevant statutory provisions, and where appropriate, their legislative history.