Te Papa's exhibits range from long-term exhibitions on New Zealand's natural environment and social history, to cultural spaces and touring/temporary exhibitions. Most are hands-on and interactive. The long term exhibitions of cultural objects focus on New Zealand history, Māori culture and New Zealand's natural world. The hands-on and interactive exhibitions focus on engaging young visitors and include out-door areas built and planted for Te Papa. The key cultural space is the Rongomaraeroa marae with unusual whakairo in its wharenui, Te Hono ki Hawaiki. All permanent exhibitions are free. Many of the temporary exhibitions are ticketed, but may have occasional free days. In 2018, the Mountains to Sea and Awesome Forces exhibits were closed, with Te Taiao Nature taking their place. This new exhibit opened on 11 May 2019, with a 1,400 square-metre exhibition focusing on New Zealand's natural environment. The exhibition retains several features of the old exhibits, such as an earthquake house simulation and a 495 kilogram (1,091 lb) Colossal squid. In 2022, the Manu Rere Moana exhibition was renewed to reflect the developments in traditional navigation since its initial installation. A full list of exhibitions can be found here. Library Te Aka Matua Library, previously a publicly accessible library, is now open only to researchers by appointment between 10am-5pm, Monday-Friday. The library is a major research and reference resource, with particular strengths in New Zealand, Māori, natural history, art, photography and museum studies. It is located on the fourth floor of the main building. Mahuki Innovation Accelerator Mahuki was Te Papa's innovation accelerator. It was an in-residence programme in which 10 teams developed solutions to challenges facing cultural institutions. Controversies The museum has sometimes been the centre of controversy. The siting of significant collections at the water's edge on reclaimed land next to one of the world's most active faults has resulted in concern by some people. There has been criticism of the "sideshow" nature of some exhibits, primarily the Time Warp section, which has closed. There has also been criticism that some exhibits were not given due reverence. For example, a major work by Colin McCahon was at one stage juxtaposed with a 1950s refrigerator in a New Zealand culture exhibition. The Māori name of the museum has caused controversy. In 1989 the Māori iwi Te Āti Awa, located near Wellington, requested that the Ngāti Whakaue iwi grant a name to the museum, which resulted in the