Arecibo Observatory (NAIC, National Astronomy and Ionosphere Center) is a radio-astronomy observatory in Puerto Rico, which hosts a 305 m aperture radio telescope now damaged. Since the damage, the observatory continues to operate its other (much smaller) radio telescopes. The concept of an updated replacement telescope at the same site remains alive.
The (damaged) major telescope (Arecibo Telescope, commonly what is meant by Arecibo Observatory) will likely be demolished. It had a non-movable antenna facing straight up, installed in a similar-sized depression in the ground. It was completed in 1963 and used until 2020 when portions of it collapsed. For nearly all its life, it was the largest existing single-aperture telescope. It used its full 305 m when observing vertically, and could be aimed to roughly 20° from the zenith, but with some reduction in its effective aperture. I figure that would support observation from just south of the celestial equator to roughly straight above Washington DC, about a third of the sky.
ALFA (The Arecibo L-band Feed Array), one of its receivers, detected radio at 1225 to 1525 MHz (nominally 1.4 GHz or 21-cm line), useful for HI observations.