ESAs Infrared Space Observatory (ISO) has detected the first known infrared-bright gravitational arcs, which may be the distorted and magnified images of distant young galaxies in collision. Before ISO, no gravitational arc had been detected at these wavelengths, so these results are a nice victory for those who, against all pessimistic predictions, bet on ISOs sensitivity to detect gravitational arcs by IR light. The newly-observed arcs number more than 30, and the galaxies they reveal are some of the farthest objects ever seen in the mid-IR. To all other telescopes these objects have remained deeply obscured by dust. This means that ISO is unveiling the hidden side of the early Universe, the processes that took place when the cosmos was about one third of its present age or even younger. The detection of a giant gravitational arc in the galaxy cluster Abell 370, plus the 30 lensed and possibly young-colliding galaxies in the galaxy cluster Abell 2390, settled the issue of whether ISO had sufficient sensitivity and resolution. In the case of Abell 2390 it took ISO an unusually long exposure-time of 16 hours to collect the light, the sensitivity of the IR camera, ISOCAM, having been pushed to the limit. These results were presented at The Universe as Seen by ISO meeting in Paris on 20-23 October 1998. This was the first major scientific conference devoted to ISO since the end of its mission in May 1998. ISO was launched on 19 November 1995 as the world's first spaceborne infrared observatory. It provided an entirely fresh perspective on the Universe before it was switched off on 16 May 1998 - well beyond the planned 18-month life. Although the supply of liquid helium, used to cool the telescope and instruments, ran out on 8 April 1998, the last scientific observation was not made until 10 May 1998. [Image Date: 1998/10] [98.10.009-002]