Complex sentence: Since the creation of an access road in 1964, thirteen telescopes funded by eleven countries have been constructed at the summit, and in April 2013, the project for a Thirty Meter Telescope project was approved.
Split into simpler sentences: Since the creation of an access road in 1964, thirteen telescopes funded by eleven countries have been constructed at the summit. In April 2013, the Thirty Meter Telescope project was approved.