The Thirty-Meter Telescope (TMT) is a proposed astronomical observatory that has become a source of controversy over its planned location on Mauna Kea in Hawai‘i. Construction of the TMT on land which is considered sacred to Native Hawaiian culture and religion attracted international coverage after October, 2014, when construction was temporarily halted as a result of protests. While construction of the telescope was set to resume on April 2 and later on June 24, 2015, it was blocked by further protests each time. The protests became a flash point for the issues of indigenous self-determination, environmental stewardship and Hawaiian sovereignty.
While the project was approved by the Board of Land and Natural Resources, the State Supreme Court of Hawai‘i invalidated the TMT building permits in December, 2015, ruling that due process was not followed when the board approved the permits. Roque de los Muchachos Observatory, La Palma, Canary Islands, in Spain, may be the alternative site if construction cannot go forward in Hawai‘i.