[sbierwagen]

LIGO did take decades to construct, like the LHC. According to LIGO's wikipedia article, it was the most expensive project ever funded by the NSF in 1994.

[neltnerb]

LIGO's size is also deceptive, the legs are kilometers long but the design is an L with the important bit being to vibrationally isolate things, maintain dimensional stability, and maintain vacuum.

ITER is likely bigger in terms of volume of concrete or actual footprint.

[lambdatronics]

Hmm, looks like ITER and LHC both use about the same amount of superconductor: around 500 tons.

[0]https://ieeexplore.ieee.org/document/1018583 [1]https://www.iter.org/mach/Magnets