The VLTI empty tunnel

An unusual 360 degree panorama view of the still empty tunnel of the Very Large Telescope Interferometer (VLTI), taken during construction in 1996. The VLTI tunnel is located below the VLT observing platform on the top of Paranal. Here the light from multiple VLT telescopes is combined interferometrically using a precise system of mirrors and delay lines. The interferometric observations allow astronomers to see details up to 25 times finer than with the individual telescopes. The VLTI first light was in 2001.

An amazing interactive virtual tour of Paranal is available here