ELT and VLT vs Colosseum

Present and future observatories compared to a marvel from the past. The ELT dome will be 100 metres in diameter, about the size of the Colosseum in Rome, but atop a 3000-metre mountaintop. For comparison, each of the four VLT unit telescopes are 25 metres high, about the size of an eight-storey building.

This picture is based on a preliminary design for the ELT.